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Triangle read by rows: T(n,k) is the number of ascent sequences of length n with first occurrence of the maximal value at position k-1.
5

%I #8 Nov 09 2012 16:06:57

%S 1,1,1,1,2,2,1,4,5,5,1,8,13,15,16,1,16,35,47,56,62,1,32,97,153,204,

%T 248,279,1,64,275,515,770,1030,1257,1423,1,128,793,1785,3000,4424,

%U 5869,7140,8100,1,256,2315,6347,12026,19582,28293,37058,44843,50887

%N Triangle read by rows: T(n,k) is the number of ascent sequences of length n with first occurrence of the maximal value at position k-1.

%C Row sums are A022493.

%C Second column are powers of 2.

%e Triangle starts:

%e [ 1] 1,

%e [ 2] 1, 1,

%e [ 3] 1, 2, 2,

%e [ 4] 1, 4, 5, 5,

%e [ 5] 1, 8, 13, 15, 16,

%e [ 6] 1, 16, 35, 47, 56, 62,

%e [ 7] 1, 32, 97, 153, 204, 248, 279,

%e [ 8] 1, 64, 275, 515, 770, 1030, 1257, 1423,

%e [ 9] 1, 128, 793, 1785, 3000, 4424, 5869, 7140, 8100,

%e [10] 1, 256, 2315, 6347, 12026, 19582, 28293, 37058, 44843, 50887,

%e ...

%Y Cf. A022493 (number of ascent sequences).

%Y Cf. A218579 (ascent sequences with last zero at position k-1), A218581 (ascent sequences with last occurrence of the maximal value at position k-1).

%Y Cf. A137251 (ascent sequences with k ascents), A218577 (ascent sequences with maximal element k), A175579 (ascent sequences with k zeros).

%K nonn,tabl

%O 1,5

%A _Joerg Arndt_, Nov 03 2012