Abbreviations:
ch: chain
SC: Single Crochet
HDC: Half Double Crochet
DC: Double Crochet
YOST: Yarn Over Slip Stitch
HDC2T: Half Double Crochet 2 Together
3 stitch cluster: 3 HDC stitches worked in the same stitch.

Chain 46

Row1: HDC in second ch from hook and all the way across.(44)

Row2: ch2, turn. HDC in next 8 stitches, 3 stitch cluster in next stitch, place marker in 2nd stitch, HDC in next 4 stitches, 3 stitch cluster in next stitch, HDC in next 16 stitches, 3 stitch cluster in next, HDC in next 4 stitches, 3 stitch cluster in next, HDC in next 8 stitches. (52)

Row3: ch2, turn. *HDC in each stitch till the first marker, 3 stitch cluster in the marked stitch* repeat from * to * till the 4th marker, HDC in each of the remaining stitches. (60)

Each round increases by 8 stitches.
Row4-12: Repeat Row3 (132)

Joining in the back
Row13: Work same as Row 3 except join with a slip stitch on top of  the first HDC of the Row. (140)


Forming arm holes

Row14: Ch2, turn, HDC in each stitch until first marker, HDC in the marker stitch, ch4, HDC in the second marker stitch. Skip all stitches in between, this forms the first armhole. HDC in each stitch till the third marker, HDC in the marked stitch, ch4, HDC in the fourth marker stitch. Skip all stitches in between. This forms the second arm hole. Join  in the round with a slip stitch. (88)

Body
Here on we will continue to work in rounds and turn after each round.

Rnd1: ch2, turn, HDC in the first stitch and in each stitch around including the ch4 in the arm holes. Join with a slip stitch (88)

Rnd2: ch2, turn, HDC in each stitch across, join with a slip stitch (88)

Rnd3-10: Repeat Rnd2 (88)

Rnd11-13:  ch1, turn, SC in each stitch across, join with a  slip stitch (88)


Rnd14: ch 1, turn, SC2 in each stitch across, join with a slip stitch. (176)

Rnd15-30: ch3, turn, DC in each stitch across, join with a slip stitch. (176)

Rnd31: ch1, turn, YOSL in each stitch across. Join with a slip stitch. (176)


Sleeves:
Repeat for both sleeves.

Join yarn in the underarm, in the middle of ch4 from Row14.

Rnd1: ch2, check the direction of work, it needs to be opposite of the previous row. HDC2T the ch spaces, HDC2T rough edge and next stitch, HDC in each stitch across from the yoke, HDC2T last stitch from yoke and rough edge, HDC2T next 2 ch spaces. Join with a slip stitch. (34)

Rnd2: ch2 turn, HDC in each  stitch across. Join with a slip stitch.

Rnd3: ch2 turn, HDC2T, HDC in each stitch, HDC2T last 2 stitches, join with a slip stitch.

Rnd4-10: Repeat Rnd2 (32)

Rnd11: ch1 turn, SC in each stitch across. Join with a slip stitch (32)

Rnd12: ch3 turn, DC2 in each stitch across. Join with a slip stitch.(64)

Rnd13-14: ch3 turn, DC in each stitch across. Join with a slip stitch. (64)

Rnd15: ch1 turn, YOSL in each stitch. Join with a slip stitch.

Edging around neck and back

Attach yarn on left bottom of back opening, SC evenly along left side, just before the corner stitch, ch5 and slip stitch in the same ch to form the button clasp. Work 3SC in the corner. 1SC in each foundation ch around the neck, work 3SC in the corner, come down the right side. Fasten off.
Attach a button.

Hide all tails and it is ready!