A002260 preceded by a column of 1's: a (1, 1, 2, 3, 4, 5,...) crescendo triangle by rows.
1, 1, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 2, 3, 4, 1, 1, 2, 3, 4, 5, 1, 1, 2, 3, 4, 5, 6, 1, 1, 2, 3, 4, 5
2 seqfan posts
Wed Dec 22 19:08:52 CET 2010 [seqfan] Re: checking a sequence before submission