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A155574 Intersection of A154777 and A092572: N = a^2 + 2b^2 = c^2 + 3d^2 for some positive integers a,b,c,d. 1
12, 19, 36, 43, 48, 57, 67, 73, 76, 97, 108, 129, 139, 144, 147, 163, 171, 172, 192, 193, 201, 211, 219, 228, 241, 268, 283, 291, 292, 300, 304, 307, 313, 324, 331, 337, 361, 379, 387, 388, 409, 417, 432, 433, 441, 457, 475, 484, 489, 499, 507, 513, 516, 523 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Subsequence of A155564 (where a,b,c,d may be zero).

LINKS

Table of n, a(n) for n=1..54.

PROG

(PARI) isA155574(n, /* optional 2nd arg allows us to get other sequences */c=[3, 2]) = { for(i=1, #c, for(b=1, sqrtint((n-1)\c[i]), issquare(n-c[i]*b^2) & next(2)); return); 1}

for( n=1, 999, isA155574(n) & print1(n", "))

CROSSREFS

Cf. A000404, A154777, A092572, A097268, A154778, A155716, A155717, A155560-A155578.

Sequence in context: A117539 A246343 A136770 * A272100 A119382 A166671

Adjacent sequences:  A155571 A155572 A155573 * A155575 A155576 A155577

KEYWORD

easy,nonn

AUTHOR

M. F. Hasler, Jan 25 2009

STATUS

approved

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Last modified May 9 10:29 EDT 2021. Contains 343732 sequences. (Running on oeis4.)