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A104274 Number of partitions of n in which odd squares occur with 2 types c,c* and with multiplicity 1. The even squares and parts that are twice the squares they occur with multiplicity 1. 0
1, 2, 2, 2, 2, 2, 2, 2, 2, 4, 6, 6, 6, 6, 6, 6, 6, 6, 8, 10, 10, 10, 10, 10, 10, 12, 14, 16, 18, 18, 18, 18, 18, 18, 22, 26, 28, 30, 30, 30, 30, 30, 30, 34, 38, 40, 42, 42, 42, 44, 48, 50, 54, 58, 60, 62, 62, 62, 66, 74, 78, 82, 86, 88, 90, 90, 90 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

FORMULA

G.f.: product_{k>0}((1+x^(2k-1)^2)/(1-x^(2k-1)^2)).

EXAMPLE

E.g. a(10)=6 because we can write it as 91,91*,9*1,9*1*,82,811*.

MAPLE

series(product((1+x^((2*k-1)^2))/(1-x^(2*k-1)^2)), k=1..100), x=0, 100);

CROSSREFS

Sequence in context: A189819 A045818 A064128 * A008857 A047935 A103795

Adjacent sequences:  A104271 A104272 A104273 * A104275 A104276 A104277

KEYWORD

easy,nonn

AUTHOR

Noureddine Chair (n.chair(AT)rocketmail.com), Feb 27 2005

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Last modified February 14 19:37 EST 2012. Contains 205663 sequences.