I needed the blanket about 160x120 cm (60x45 inches).

This pattern is a multiple of 16 and plus an additional 20 for the border. For my blanket I cast on 180 stitches (160+20)

Border Rows 1-12: Seed Stitch (K1, P1 for border)

Now start with the pattern (view the picture):
Row 1, 3, 5 and 7:
Seed Stitch for 8 stitches (K1, P1), place marker for border
* K4, P2, K8, P2 * till last 12 stitches, K4
Place marker for border and Seed Stitch to end (K1, P1)

Row 2 and all even rows:
8 sts Seed Stitch, * P4, K2, P8, K2 * till last 12 sts, P4, Seed Stitch to end

Row 9: 8 sts Seed Stitch, * K4, P2, slip 4 sts on cable needle and hold in BACK. K4 from left needle, K4 from the cable needle, P2 * till last 12 sts, P4, Seed Stitch to end

Row 10: 8 sts Seed Stitch, * P4, K2, P8, K2 * till last 12 sts, P4, Seed Stitch to end

Repeat Rows 2 to 10 until blanket measures desired length.

Repeat Border Rows 1-12 and bind off knit-wise.
Assemble ends and make sure to block.