login
A113909
Square table of odd numbers which are neither squares nor one less than squares, read by antidiagonals.
0
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.
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
KEYWORD
nonn,tabl
AUTHOR
Pierre CAMI, Jan 29 2006
EXTENSIONS
Edited by N. J. A. Sloane, Jul 18 2009
STATUS
approved