A113909 Square table of odd numbers which are neither squares nor one less than squares, read by antidiagonals.

5, 7, 11, 13, 17, 19, 21, 23, 27, 29, 31, 33, 37, 39, 41, 43, 45, 47, 51, 53, 55, 57, 59, 61, 65, 67, 69, 71, 73, 75, 77, 79, 83, 85, 87, 89, 91, 93, 95, 97, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 123, 125, 127, 129, 131

Offset

1,1

Comments

All such numbers may be written as n*(n+1)-k or n*(n+1)+k with k odd < n and n > 1.

Links

Table of n, a(n) for n=1..55.

Formula

for l=1 to n for c=l to n T(l, c)=(l+c)*(l+c+1)-2*l+1 next c next l for c=1 to n for l=c+1 to n T(l, c)=(l+c-1)*(l+c)+2*c-1 next l next c

Crossrefs

Sequence in context: A342105 A035035 A256387 * A111906 A348471 A101550

Adjacent sequences: A113906 A113907 A113908 * A113910 A113911 A113912

Keyword

nonn,tabl

Author

Pierre CAMI, Jan 29 2006

Extensions

Edited by N. J. A. Sloane, Jul 18 2009

Status

approved