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A155567
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Intersection of A002479 and A020669 : N = a^2 + 2b^2 = c^2 + 5d^2 for some integers a,b,c,d.
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1
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0, 1, 4, 6, 9, 16, 24, 25, 36, 41, 49, 54, 64, 81, 86, 89, 96, 100, 121, 129, 134, 144, 150, 164, 166, 169, 196, 201, 214, 216, 225, 241, 246, 249, 256, 281, 289, 294, 321, 324, 326, 344, 356, 361, 369, 384, 400, 401, 409, 441, 449, 454, 484, 486, 489, 516, 521
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OFFSET
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1,3
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COMMENTS
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Contains A155577 as a subsequence (obtained by restricting a,b,c,d to be nonzero). Also contains A000290 (squares) as subsequence.
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LINKS
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PROG
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(PARI) isA155567(n, /* use optional 2nd arg to get other analogous sequences */c=[5, 2]) = { for(i=1, #c, for(b=0, sqrtint(n\c[i]), issquare(n-c[i]*b^2) & next(2)); return); 1}
for( n=1, 600, isA155567(n) & print1(n", "))
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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