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A022880 The number of numbers [ [ ix ]jx ] that equal n, where i >= 1, j >= 1 and x=sqrt(2). 0
1, 2, 0, 1, 3, 0, 2, 2, 2, 0, 4, 2, 0, 3, 2, 4, 0, 1, 4, 0, 3, 5, 0, 1, 4, 2, 0, 4, 3, 0, 4, 1, 6, 0, 3, 3, 0, 2, 6, 0, 2, 4, 2, 0, 6, 3, 0, 2, 4, 7, 0, 1, 4, 0, 2, 5, 2, 0, 6, 2, 0, 5, 5, 0, 3, 1, 8, 0, 3, 5, 0, 1, 5, 2, 0, 4, 4, 0, 8, 3, 0, 3, 2, 7, 0, 1, 4, 0, 5, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(n) = 0 if and only if n is in the Beatty sequence A001952.
LINKS
PROG
(PARI) a(n)=sum(i=1, sqrtint((n^2+2*n+2)^2\8), my(k=sqrtint(2*i^2)); sqrtint(sqrtint( (n+1)^2\k^2\2)^2*2*k^2)==n) \\ Charles R Greathouse IV, Mar 05 2013
CROSSREFS
Sequence in context: A373118 A219311 A363393 * A366614 A128097 A328096
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified June 15 06:51 EDT 2024. Contains 373402 sequences. (Running on oeis4.)