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A081056 Number of partitions of 2n+1 in which no parts are multiples of 4. 1
1, 3, 6, 12, 22, 38, 64, 105, 166, 258, 395, 592, 876, 1280, 1846, 2636, 3728, 5222, 7256, 10006, 13696, 18624, 25169, 33808, 45164, 60022, 79366, 104457, 136870, 178572, 232044, 300368, 387366, 497804, 637568, 813910, 1035792, 1314214 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

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

FORMULA

G.f.: (sum_{n>=0} x^A074377(n))/(sum_n (-x)^n^2).

PROG

(PARI) a(n)=local(X); if(n<0, 0, X=x+x^2*O(x^(2*n)); polcoeff(eta(X^4)/eta(X), 2*n+1))

CROSSREFS

a(n)=A001935(2n+1).

Sequence in context: A139422 A062483 A174013 * A066982 A179906 A018078

Adjacent sequences:  A081053 A081054 A081055 * A081057 A081058 A081059

KEYWORD

nonn,easy

AUTHOR

Michael Somos, Mar 03 2003

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Last modified February 16 21:51 EST 2012. Contains 205978 sequences.