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A367591
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Expansion of 1/((1-x) * (1-3*x)^3).
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2
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1, 10, 64, 334, 1549, 6652, 27064, 105796, 401041, 1483606, 5380840, 19198306, 67559437, 234963352, 808919632, 2760370984, 9346519297, 31429487170, 105039380080, 349114288150, 1154561484781, 3801030845140, 12462203297224, 40705156945324, 132494756301649
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = ((2*n^2+4*n+3) * 3^(n+1) - 1)/8.
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PROG
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(PARI) a(n) = ((2*n^2+4*n+3)*3^(n+1)-1)/8;
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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