This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A218581 #8 Nov 09 2012 17:56:39 %S A218581 1,0,2,0,1,4,0,1,4,10,0,1,6,15,31,0,1,10,29,62,115,0,1,18,63,148,288, %T A218581 496,0,1,34,149,392,826,1496,2437,0,1,66,375,1120,2592,5036,8615, %U A218581 13435,0,1,130,989,3392,8698,18332,33391,54548,82127 %N A218581 Triangle read by rows: T(n,k) is the number of ascent sequences of length n with last occurrence of the maximal value at position k-1. %C A218581 Row sums are A022493. %e A218581 Triangle starts: %e A218581 [ 1] 1, %e A218581 [ 2] 0, 2, %e A218581 [ 3] 0, 1, 4, %e A218581 [ 4] 0, 1, 4, 10, %e A218581 [ 5] 0, 1, 6, 15, 31, %e A218581 [ 6] 0, 1, 10, 29, 62, 115, %e A218581 [ 7] 0, 1, 18, 63, 148, 288, 496, %e A218581 [ 8] 0, 1, 34, 149, 392, 826, 1496, 2437, %e A218581 [ 9] 0, 1, 66, 375, 1120, 2592, 5036, 8615, 13435, %e A218581 [10] 0, 1, 130, 989, 3392, 8698, 18332, 33391, 54548, 82127, %e A218581 [11] 0, 1, 258, 2703, 10768, 30768, 70868, 138635, 239688, 377001, 551384, %e A218581 ... %Y A218581 Cf. A022493 (number of ascent sequences). %Y A218581 Cf. A218579 (ascent sequences with last zero at position k-1), A218580 (ascent sequences with first occurrence of the maximal value at position k-1). %Y A218581 Cf. A137251 (ascent sequences with k ascents), A218577 (ascent sequences with maximal element k), A175579 (ascent sequences with k zeros). %K A218581 nonn,tabl %O A218581 1,3 %A A218581 _Joerg Arndt_, Nov 03 2012