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A348643
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a(n) = (16*n + 1)*(2592*n^2 + 288*n + 7).
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3
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7, 49079, 361383, 1185751, 2771015, 5366007, 9219559, 14580503, 21697671, 30819895, 42196007, 56074839, 72705223, 92335991, 115215975, 141594007, 171718919, 205839543, 244204711, 287063255, 334664007, 387255799, 445087463, 508407831, 577465735, 652510007, 733789479, 821552983
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OFFSET
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0,1
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COMMENTS
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a(n) is the entry (1,1) of a family of unimodular matrices none of whose entries is 1 or -1, such that when each entry of the matrix is replaced by its cube, the resulting matrix is also unimodular.
In these matrices, the entries (1,3) and (3,1) = 2; the entries (2,3) and (3,2) = 3; the entry (3,3) = 0.
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LINKS
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PROG
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(PARI) a(n) = (16*n + 1)*(2592*n^2 + 288*n + 7);
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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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