

A218580


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 k1.


5



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, 248, 279, 1, 64, 275, 515, 770, 1030, 1257, 1423, 1, 128, 793, 1785, 3000, 4424, 5869, 7140, 8100, 1, 256, 2315, 6347, 12026, 19582, 28293, 37058, 44843, 50887
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OFFSET

1,5


COMMENTS

Row sums are A022493.
Second column are powers of 2.


LINKS

Table of n, a(n) for n=1..55.


EXAMPLE

Triangle starts:
[ 1] 1,
[ 2] 1, 1,
[ 3] 1, 2, 2,
[ 4] 1, 4, 5, 5,
[ 5] 1, 8, 13, 15, 16,
[ 6] 1, 16, 35, 47, 56, 62,
[ 7] 1, 32, 97, 153, 204, 248, 279,
[ 8] 1, 64, 275, 515, 770, 1030, 1257, 1423,
[ 9] 1, 128, 793, 1785, 3000, 4424, 5869, 7140, 8100,
[10] 1, 256, 2315, 6347, 12026, 19582, 28293, 37058, 44843, 50887,
...


CROSSREFS

Cf. A022493 (number of ascent sequences).
Cf. A218579 (ascent sequences with last zero at position k1), A218581 (ascent sequences with last occurrence of the maximal value at position k1).
Cf. A137251 (ascent sequences with k ascents), A218577 (ascent sequences with maximal element k), A175579 (ascent sequences with k zeros).
Sequence in context: A098977 A247311 A113547 * A259697 A115313 A048942
Adjacent sequences: A218577 A218578 A218579 * A218581 A218582 A218583


KEYWORD

nonn,tabl


AUTHOR

Joerg Arndt, Nov 03 2012


STATUS

approved



