OFFSET
0,3
LINKS
Robert Israel, Table of n, a(n) for n = 0..2000
FORMULA
a(n) ~ (4/9)*n^3 + (2/3)*n^2 + (4*zeta(-1/2)/3)*n^(3/2) + (11/36)*n + zeta(-1/2)*sqrt(n). - Robert Israel, Oct 28 2020
MAPLE
f:= n -> floor(add(sqrt(i), i=1..n)^2):
map(f, [$0..100]); # Robert Israel, Oct 28 2020
MATHEMATICA
a[n_] := Floor[(Sum[ Sqrt[k], {k, 0, n}])^2]; Array[a, 50, 0]
PROG
(PARI) a(n) = floor(sum(j=0, n, sqrt(j))^2); \\ Michel Marcus, Oct 26 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Oct 21 2020
STATUS
approved