OFFSET
0,4
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..9998
Hugo Pfoertner, Logarithmic plot of a(n) vs n, n <= 10^5, lower envelope of terms > 0 shown in red, zoom for details.
MATHEMATICA
Array[PolygonalNumber[#^2] - Floor[Sqrt[(#^4 + #^2)/2]]^2 &, 55, 0] (* Michael De Vlieger, Jun 02 2024 *)
PROG
(PARI) a(n) = my(T=(n^4+n^2)/2); T-sqrtint(T)^2
(Python)
from sympy import integer_nthroot
def A373330(n): return (T:=(n**4 + n**2) // 2)-(integer_nthroot(T, 2)[0])**2
# Karl-Heinz Hofmann, Jul 01 2024
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Hugo Pfoertner, Jun 02 2024
STATUS
approved