

A111099


Sum of even Fermat coefficients rounded to nearest integer.


0



0, 1, 2, 4, 9, 20, 45, 105, 246, 583, 1393, 3355, 8133, 19825, 48554, 119412, 294761, 729980, 1813107, 4515225, 11271198, 28196896, 70679137, 177487714, 446446560, 1124706145, 2837445500, 7167878628, 18129622761, 45907772900, 116372614251
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OFFSET

1,3


LINKS

Table of n, a(n) for n=1..31.
P. A. Piza, Fermat coefficients, Math. Mag., 27 (1954), 141146.


FORMULA

Following Piza's definition for the Fermat coefficients: (n:c)=binomial(2nc, c1)/c, a(n)= Round( sum_{0<c<=n & c even} (n:c) ).


MAPLE

FermatCoeff:=(n, c)>binomial(2*nc, c1)/c:
seq(round(add(FermatCoeff(n, 2*r), r=1..floor(n/2))), n=1..40);


CROSSREFS

Sequence in context: A329276 A308435 A188460 * A000632 A090245 A274965
Adjacent sequences: A111096 A111097 A111098 * A111100 A111101 A111102


KEYWORD

nonn


AUTHOR

Pab Ter (pabrlos2(AT)yahoo.com), Oct 13 2005


STATUS

approved



