OFFSET
1,2
COMMENTS
Or, 1 together with composite numbers of the form i^2+(i+1)^2. See A012132. - N. J. A. Sloane, Feb 29 2020
FORMULA
a(n) = 2n^2 + O(n^2/log n). - Charles R Greathouse IV, Mar 21 2014
EXAMPLE
a(1)=(1^2+1)/2=1; a(2)=(7^2+1)/2=25.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Juri-Stepan Gerasimov, Oct 06 2009
EXTENSIONS
Replaced 6261 by 6161 - R. J. Mathar, Oct 07 2009
STATUS
approved