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A081055
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Number of partitions of 2n in which no parts are multiples of 4.
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1
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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; internal format)
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OFFSET
| 0,2
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COMMENTS
| Euler transform of period 16 sequence [2,1,3,1,3,0,2,0,2,0,3,1,3,1,2,0,...].
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FORMULA
| G.f.: (sum_{n>=0} x^A074378(n))/(sum_n (-x)^n^2).
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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))
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CROSSREFS
| a(n)=A001935(2n).
Sequence in context: A114080 A090676 A000291 * A034446 A174511 A034452
Adjacent sequences: A081052 A081053 A081054 * A081056 A081057 A081058
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KEYWORD
| nonn,easy
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AUTHOR
| Michael Somos, Mar 03 2003
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