A085267 - OEIS

A085267

Numbers having at least two representations as sum of a squarefree number and a nonzero square.

6, 7, 10, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Numbers n such that A085263(a(n)) > 1.

Conjecture: for n > 50, a(n) = n + 11. - Charles R Greathouse IV, Oct 26 2011

LINKS

Table of n, a(n) for n=1..67.

Eric Weisstein's World of Mathematics, Square Number

Eric Weisstein's World of Mathematics, Squarefree

PROG

(PARI) is(n)=my(t); forstep(k=sqrtint(n-1), 1, -1, if(issquarefree(n-k^2), if(t++>1, return(1)))); 0 \\ Charles R Greathouse IV, Mar 12 2012