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A176712
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a(n) = 16*n^4 + 256*n^3 + 1160*n^2 + 1088*n + 285.
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3
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285, 2805, 9405, 22197, 43677, 76725, 124605, 190965, 279837, 395637, 543165, 727605, 954525, 1229877, 1559997, 1951605, 2411805, 2948085, 3568317, 4280757, 5094045, 6017205, 7059645, 8231157, 9541917, 11002485, 12623805, 14417205
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OFFSET
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0,1
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COMMENTS
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Since the formula can be factored, there are no primes in the sequence.
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LINKS
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FORMULA
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a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + 384 for n > 3; a(0)=21, a(1)=285, a(2)=1365, a(3)=4221.
G.f.: 3*(95 + 460*x - 590*x^2 + 124*x^3 + 39*x^4)/(1-x)^5.
a(n) = (2*n+1)*(2*n+15)*(4*n^2+32*n+19).
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MATHEMATICA
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Table[16n^4+256n^3+1160n^2+1088n+285, {n, 0, 30}] (* or *) LinearRecurrence[ {5, -10, 10, -5, 1}, {285, 2805, 9405, 22197, 43677}, 30] (* Harvey P. Dale, Jan 10 2017 *)
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PROG
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(Magma) [ 16*n^4+256*n^3+1160*n^2+1088*n+285: n in [0..27] ];
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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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