A174804 - OEIS

%I #17 Feb 02 2023 04:52:07

%S 0,1,4,6,16,30,36,42,48,81,120,132,144,156,168,180,256,340,360,380,

%T 400,420,440,460,480,625,780,810,840,870,900,930,960,990,1020,1050,

%U 1296,1554,1596,1638,1680,1722,1764,1806,1848,1890,1932,1974,2016,2401,2800

%N a(n) = n*ceiling(sqrt(n))*floor(sqrt(n)).

%C As a(n^2) = n^4, A000583 is a subsequence. - _Bernard Schott_, Feb 01 2023

%F a(n) = n*A000196(n)*A003059(n). - _Michel Marcus_, Feb 14 2018

%t f[n_]:=n*Floor[Sqrt[n]]*Ceiling[Sqrt[n]];Table[f[n],{n,0,5!}]

%o (PARI) a(n) = n*sqrtint(n)*ceil(sqrt(n)); \\ _Michel Marcus_, Feb 14 2018

%o (Python)

%o from math import isqrt

%o def A174804(n): return n*(n if (k:=(m:=isqrt(n))**2)==n else k+m) # _Chai Wah Wu_, Jul 29 2022

%Y Cf. A000196, A000583, A003059, A038760, A174803.

%K nonn

%O 0,3

%A _Vladimir Joseph Stephan Orlovsky_, Mar 29 2010