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A046949
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Sizes of successive balls in D_4 lattice.
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2
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1, 25, 49, 145, 169, 313, 409, 601, 625, 937, 1081, 1369, 1465, 1801, 1993, 2569, 2593, 3025, 3337, 3817, 3961, 4729, 5017, 5593, 5689, 6433, 6769, 7729, 7921, 8641, 9217, 9985, 10009, 11161, 11593, 12745, 13057, 13969, 14449, 15793
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OFFSET
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0,2
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COMMENTS
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The subsequence of primes in this partial sum begins: 313, 409, 601, 937, 1801, 1993, 2593, 4729, 5689, 8641, 10009, 11161, 11593, 14449. [From Jonathan Vos Post, Feb 18 2010]
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LINKS
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Table of n, a(n) for n=0..39.
Index entries for sequences related to D_4 lattice
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MATHEMATICA
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A004011 = Join[{1}, Table[24*Sum[d*Mod[d, 2], {d, Divisors[n]}], {n, 1, 40}]]; Accumulate[A004011](* Jean-François Alcover, Apr 25 2012 *)
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PROG
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(PARI) B=1; bl=[ 1 ]; for (n=1, 200, t1=divisors(2*n); t2=0; for (i=1, length(t1), if( t1[ i ]%4 <> 0, t2=t2+t1[ i ])); B=B+8*t2; bl=concat(bl, B)); bl
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CROSSREFS
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Partial sums of A004011.
Sequence in context: A131706 A110015 A110586 * A137659 A020325 A108604
Adjacent sequences: A046946 A046947 A046948 * A046950 A046951 A046952
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane.
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STATUS
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approved
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