A111099 Sum of even Fermat coefficients rounded to nearest integer.

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

Offset

1,3

Links

Table of n, a(n) for n=1..31.

P. A. Piza, Fermat coefficients, Math. Mag., 27 (1954), 141-146.

Formula

Following Piza's definition for the Fermat coefficients: (n:c)=binomial(2n-c, c-1)/c, a(n)= Round( sum_{0<c<=n & c even} (n:c) ).

Maple

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

Crossrefs

Sequence in context: A308435 A352018 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