A022880 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A022880

The number of numbers [ [ ix ]jx ] that equal n, where i >= 1, j >= 1 and x=sqrt(2).

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

Table of n, a(n) for n=1..90.

Index entries for sequences related to Beatty sequences

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

Adjacent sequences: A022877 A022878 A022879 * A022881 A022882 A022883

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved