OFFSET
0,3
FORMULA
a(n) = (ceiling(sqrt(2*n + 1)))^2 - (2*n + 1).
PROG
(Python)
from math import isqrt
def A348596(n): return (isqrt(2*n)+1)**2-2*n-1 # Chai Wah Wu, Feb 22 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ryan Jean, Feb 22 2022
EXTENSIONS
Edited by N. J. A. Sloane, Feb 22 2022
STATUS
approved