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A106845
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n^2 * (n^3 + 2n^2 + 7n - 2) / 8.
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0
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0, 1, 14, 72, 244, 650, 1476, 2989, 5552, 9639, 15850, 24926, 37764, 55432, 79184, 110475, 150976, 202589, 267462, 348004, 446900, 567126, 711964, 885017, 1090224, 1331875, 1614626, 1943514, 2323972, 2761844, 3263400, 3835351, 4484864
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| a(n) = Sum {1<=k,l,m<=n; k+l+m divisible by n} klm.
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PROG
| (PARI) a(n)=if(n<1, 0, sum(k=1, n, sum(l=1, n, sum(m=1, n, if((k+l+m)%n==0, k*l*m))))) /* Michael Somos May 16 2005 */
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CROSSREFS
| Sequence in context: A186707 A074086 A205335 * A205328 A205590 A146563
Adjacent sequences: A106842 A106843 A106844 * A106846 A106847 A106848
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KEYWORD
| nonn
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AUTHOR
| Ralf Stephan, May 06 2005
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