A155573 Intersection of A000404, A154777 and A092572: N = a^2 + b^2 = c^2 + 2d^2 = e^2 + 3f^2 for some positive integers a,b,c,d,e,f.

73, 97, 193, 241, 292, 313, 337, 388, 409, 433, 457, 577, 601, 657, 673, 769, 772, 873, 900, 937, 964, 1009, 1033, 1129, 1153, 1156, 1168, 1201, 1249, 1252, 1297, 1321, 1348, 1489, 1521, 1552, 1609, 1636, 1657, 1732, 1737, 1753, 1777, 1801, 1825, 1828

Offset

1,1

Links

Table of n, a(n) for n=1..46.

Prog

(PARI) isA155573(n, /* optional 2nd arg allows us to get other sequences */c=[3, 2, 1]) = { 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, 1999, isA155573(n) & print1(n", "))

Crossrefs

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

Sequence in context: A168110 A139972 A268426 * A107008 A141375 A140621

Adjacent sequences: A155570 A155571 A155572 * A155574 A155575 A155576

Keyword

easy,nonn

Author

M. F. Hasler, Jan 25 2009

Status

approved