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A261343
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50-gonal numbers: a(n) = 48*n*(n-1)/2 + n.
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1
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0, 1, 50, 147, 292, 485, 726, 1015, 1352, 1737, 2170, 2651, 3180, 3757, 4382, 5055, 5776, 6545, 7362, 8227, 9140, 10101, 11110, 12167, 13272, 14425, 15626, 16875, 18172, 19517, 20910, 22351, 23840, 25377, 26962, 28595, 30276, 32005, 33782, 35607, 37480
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OFFSET
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0,3
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COMMENTS
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According to the common formula for the polygonal numbers: (s-2)*n*(n-1)/2 + n (here s = 50).
96*a(n) + 23^2 is a square.
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LINKS
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FORMULA
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a(n) = n*(24*n - 23).
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MAPLE
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MATHEMATICA
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PolygonalNumber[50, Range[0, 40]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Oct 11 2019 *)
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PROG
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(JavaScript) function a(n){return 48*n*(n-1)/2+n}
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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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