login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A051166
Sequence is defined by property that binomial transform of (a0,a1,a2,a3,...) = (a0,a0,a0,a1,a1,a1,a2,a2,a2,a3,a3,a3,...).
5
1, 0, 0, -1, 3, -6, 10, -15, 21, -29, 45, -90, 224, -609, 1677, -4559, 12135, -31542, 80086, -199035, 485469, -1165105, 2757369, -6446778, 14913052, -34175805, 77672325, -175228740, 392711166, -874901088, 1938704130, -4275110880, 9385473510, -20521355211, 44704157499, -97055415324
OFFSET
0,5
LINKS
N. J. A. Sloane, Transforms
MAPLE
a:= proc(n) option remember; add(`if`(k<3, 1,
a(iquo(k, 3)))*(-1)^(n-k)*binomial(n, k), k=0..n)
end:
seq(a(n), n=0..45); # Alois P. Heinz, Jul 08 2015
MATHEMATICA
a[n_] := a[n] = Sum[If[k<3, 1, a[Quotient[k, 3]]]*(-1)^(n-k)*Binomial[n, k], {k, 0, n}];
Table[a[n], {n, 0, 45}] (* Jean-François Alcover, Apr 04 2017, after Alois P. Heinz *)
CROSSREFS
KEYWORD
easy,sign,eigen
EXTENSIONS
More terms from Vladeta Jovovic, Jul 26 2002
STATUS
approved