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A081055 Number of partitions of 2n in which no parts are multiples of 4. 4
1, 2, 4, 9, 16, 29, 50, 82, 132, 208, 320, 484, 722, 1060, 1539, 2210, 3138, 4416, 6163, 8528, 11716, 15986, 21666, 29190, 39104, 52098, 69060, 91106, 119634, 156416, 203664, 264128, 341256, 439321, 563600, 720648, 918530, 1167154, 1478720 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Euler transform of period 16 sequence [2,1,3,1,3,0,2,0,2,0,3,1,3,1,2,0,...].

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..10000

FORMULA

G.f.: (sum_{n>=0} x^A074378(n))/(sum_n (-x)^n^2).

a(n) = A001935(2n).

a(n) ~ exp(Pi*sqrt(n)) / (2^(7/2) * n^(3/4)). - Vaclav Kotesovec, Nov 15 2017

PROG

(PARI) a(n)=local(X); if(n<0, 0, X=x+x*O(x^(2*n)); polcoeff(eta(X^4)/eta(X), 2*n))

CROSSREFS

Cf. A001935, A074378, A081056.

Sequence in context: A090676 A261240 A000291 * A034446 A174511 A034452

Adjacent sequences:  A081052 A081053 A081054 * A081056 A081057 A081058

KEYWORD

nonn,easy

AUTHOR

Michael Somos, Mar 03 2003

STATUS

approved

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Last modified July 22 10:03 EDT 2019. Contains 325219 sequences. (Running on oeis4.)