A143962 Binomial transform of A066247 (characteristic function of composite numbers).

0, 0, 0, 0, 1, 5, 16, 42, 99, 220, 476, 1023, 2201, 4732, 10102, 21284, 44103, 89845, 180354, 358226, 707561, 1396560, 2764906, 5501807, 11005363, 22101301, 44470622, 89475559, 179753753, 360325116, 720748862, 1439561539, 2873846383, 5740501232, 11484167472

Offset

0,6

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

N. J. A. Sloane, Transforms

Formula

a(n) = Sum_{k=4..n} C(n,k)*A066247(k).

Example

a(7) = [35,21,7,1]*[1,0,1,0] = 35+7 = 42.

Maple

a:= proc(n) local k, s; s:=0; for k from 4 to n do if not isprime(k) then s:= s+ binomial(n, k) fi od; s; end: seq (a(n), n=0..40);

Mathematica

a[n_] := Module[{k, s = 0}, For[k = 4, k <= n, k++, If[!PrimeQ[k], s = s + Binomial[n, k]]]; s]; Table [a[n], {n, 0, 40}] // Flatten (* Jean-François Alcover, Dec 30 2013, translated from Maple *)

Crossrefs

Cf. A007318, A066247.

Sequence in context: A255135 A055796 A002662 * A321959 A066634 A241794

Adjacent sequences: A143959 A143960 A143961 * A143963 A143964 A143965

Keyword

nonn

Author

Alois P. Heinz, Sep 05 2008

Status

approved