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

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

Crossrefs

Cf. A085265, A085266.

Sequence in context: A006364 A037301 A163247 * A374528 A372587 A118957

Adjacent sequences: A085264 A085265 A085266 * A085268 A085269 A085270

Keyword

nonn

Author

Reinhard Zumkeller, Jun 23 2003

Status

approved