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A134154
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a(n) = 15n^2 - 9n + 1.
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11
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1, 7, 43, 109, 205, 331, 487, 673, 889, 1135, 1411, 1717, 2053, 2419, 2815, 3241, 3697, 4183, 4699, 5245, 5821, 6427, 7063, 7729, 8425, 9151, 9907, 10693, 11509, 12355, 13231, 14137, 15073, 16039, 17035, 18061, 19117, 20203, 21319, 22465, 23641
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OFFSET
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0,2
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COMMENTS
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LINKS
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FORMULA
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1) a(n) = 15n^2 - 9n + 1 2) a(n) = (3(5n + 3)^2 + 3 (5n + 3) - 1)/5 3) a(n) = sum[k^4]/sum[k^2], {k, 1, 5m + 3}]
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MATHEMATICA
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1) Table[1 - 9 n + 15 n^2, {n, 0, 50}] 2) Table[Sum[k^4, {k, 1, 5m + 3}]/Sum[k^2, {k, 1, 5m + 3}], {m, 0, 30}] (*Artur Jasinski*)
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PROG
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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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