



1, 2, 3, 13, 11, 49, 27, 141, 523, 3081, 923, 5509, 1371, 7617, 24391, 84933, 14795, 110329, 20859, 142101, 499843, 1858209, 241211, 2312077, 8417451
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..25.


FORMULA

a(n) = sum_{m=1..n} A117683(n,m).


MATHEMATICA

cf[0] = 1; cf[n_Integer?Positive] := cf[n] = f[n]*cf[n  1] bf[n_Integer?Positive, m_Integer?Positive] := bf[n, m] = cf[n]/(cf[m]*cf[n  m]) b = Table[Table[bf[n, m], {m, 1, n}], {n, 1, 10}] MatrixForm[b] Flatten[b] c = Table[Apply[Plus, Table[bf[n, m], {m, 1, n}]], {n, 1, 25}] ListPlot[c, PlotJoined > True]


CROSSREFS

Sequence in context: A046421 A132365 A129671 * A056445 A171483 A100385
Adjacent sequences: A117681 A117682 A117683 * A117685 A117686 A117687


KEYWORD

nonn


AUTHOR

Roger L. Bagula, Apr 12 2006


EXTENSIONS

Description simplified, offset corrected by the Assoc. Eds. of the OEIS, Jun 27 2010


STATUS

approved



