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Intersection of A002479 inter A002481: N = a^2 + 2b^2 = c^2 + 6d^2 for some integers a,b,c,d.
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%I #3 Jul 14 2012 11:32:23

%S 0,1,4,6,9,16,22,24,25,33,36,49,54,64,73,81,88,96,97,100,118,121,132,

%T 144,150,166,169,177,193,196,198,214,216,225,241,249,256,262,289,292,

%U 294,297,313,321,324,337,352,358,361,384,388,393,400,409,433,438,441

%N Intersection of A002479 inter A002481: N = a^2 + 2b^2 = c^2 + 6d^2 for some integers a,b,c,d.

%C Contains A155709 as a subsequence (obtained by restricting a,b,c,d to be nonzero). Also contains A000290 (squares) as subsequence.

%o (PARI) isA155569(n,/* use optional 2nd arg to get other analogous sequences */c=[6,2]) = { for(i=1,#c, for(b=0,sqrtint(n\c[i]), issquare(n-c[i]*b^2) & next(2)); return);1}

%o for( n=0,500, isA155569(n) & print1(n","))

%Y Cf. A001481, A002479, A003136, A002481, A020668 ff.

%K easy,nonn

%O 1,3

%A _M. F. Hasler_, Jan 25 2009