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A247763 The number of representations of n as n=x^2-2^y, x>0, y>=0. 2
1, 1, 1, 1, 1, 0, 1, 2, 1, 0, 0, 1, 0, 1, 1, 1, 4, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 2, 2, 1, 1, 1, 0, 0, 0, 0, 2, 0, 0, 0, 1, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 2, 0, 0, 4, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 2, 0, 0, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,8

COMMENTS

The n for which the count is nonzero are listed in A051204.

LINKS

R. J. Mathar, Table of n, a(n) for n = 1..136

Maohua Le, On the number of solutions of the generalized Ramanujan-Nagell equation x^2-d=2^(n+2), Acta Arithm. 60 (1991) 149.

R. J. Mathar, The number of representations of n of the form n=x^2-2^y [PDF]

Nicholas Tzanakis, On the diophantine equation y^2-d=2^k, J. Number Theory 17 (1983) 144.

CROSSREFS

Cf. A051205.

Sequence in context: A082926 A060564 A031267 * A065360 A101676 A056560

Adjacent sequences:  A247760 A247761 A247762 * A247764 A247765 A247766

KEYWORD

nonn

AUTHOR

R. J. Mathar, Oct 19 2014

STATUS

approved

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Last modified April 20 09:59 EDT 2019. Contains 322309 sequences. (Running on oeis4.)