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A139546
Numbers of form x^2+5y^2 (x>=0,y>=0) with repetition.
0
0, 1, 4, 5, 6, 9, 9, 14, 16, 20, 21, 21, 24, 25, 29, 30, 36, 36, 41, 45, 45, 46, 49, 49, 54, 54, 56, 61, 64, 69, 69, 70, 80, 81, 81, 81, 84, 84, 86, 89, 94, 96, 100, 101, 105, 105, 109, 116, 120, 121, 125, 126, 126, 126, 129, 129, 134, 141, 141, 144, 144, 145, 149, 150
OFFSET
1,3
COMMENTS
Primes in the sequence occur only once.
REFERENCES
David A. Cox, "Primes of the Form x^2 + n y^2", Wiley, 1989.
EXAMPLE
0 = 0^2+5*0^2,
9 = 2^2+5*1^2 = 3^2+5*0^2,
81 = 1^2+5*4^2 = 6^2+5*3^2 = 9^2+5*0^2,
441: {x,y}={6,9},{11,8},{14,7},{19,4},{21,0}.
CROSSREFS
Cf. A033205.
Sequence in context: A195355 A049466 A196551 * A369352 A308886 A029776
KEYWORD
nonn
AUTHOR
Zak Seidov, Apr 26 2008
STATUS
approved