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A118807 Number of partitions of n having no parts with multiplicity 3. 11
1, 1, 2, 2, 5, 6, 9, 12, 19, 24, 34, 43, 62, 77, 105, 132, 177, 220, 287, 356, 462, 570, 723, 888, 1121, 1370, 1705, 2074, 2570, 3111, 3816, 4601, 5617, 6743, 8170, 9777, 11794, 14058, 16858, 20029, 23932, 28334, 33692, 39772, 47133, 55468, 65471, 76840 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Column 0 of A118806.

Infinite convolution product of [1,1,1,0,1,1,1,1,1,1] aerated n-1 times. i.e. [1,1,1,0,1,1,1,1,1,1] * [1,0,1,0,1,0,0,0,1,0] * [1,0,0,1,0,0,1,0,0,0] * ... [From Mats Granvik, Gary W. Adamson, Aug 07 2009]

LINKS

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

FORMULA

G.f.: product(1+x^j+x^(2j)+x^(4j)/(1-x^j), j=1..infinity).

a(n) = A000041(n)-A183560(n) = A183568(n,0)-A183568(n,3). - Alois P. Heinz, Oct 09 2011

EXAMPLE

a(6) = 9 because among the 11 (=A000041(6)) partitions of 6 only [2,2,2] and [3,1,1,1] have parts with multiplicity 3.

MAPLE

g:=product(1+x^j+x^(2*j)+x^(4*j)/(1-x^j), j=1..60): gser:=series(g, x=0, 55): seq(coeff(gser, x, n), n=0..50);

CROSSREFS

Cf. A000041, A118806, A007690, A116645, A183560, A183568.

Sequence in context: A054255 A063177 A034803 * A098507 A097066 A035548

Adjacent sequences:  A118804 A118805 A118806 * A118808 A118809 A118810

KEYWORD

nonn

AUTHOR

Emeric Deutsch (deutsch(AT)duke.poly.edu), Apr 29 2006

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Last modified February 16 23:45 EST 2012. Contains 205978 sequences.