A031335 a(n)=least k such that n begins at s(k), where s=A031324.
1, 2, 3, 11, 4, 25, 23, 5, 15, 26, 55, 1, 6, 16, 31, 42, 52, 40, 78, 98, 8, 93, 2, 118, 35, 106, 132, 57, 94, 113, 77, 7, 20, 10, 3, 64, 22, 307, 75, 100, 39, 18, 196, 17, 11, 50, 395, 244, 138, 68, 46, 117, 297, 345, 12, 368, 60, 4, 32, 375
Offset: 1