A373329 - OEIS

%I #19 Jun 02 2024 13:24:58

%S 0,1,3,6,11,18,25,35,45,57,71,85,102,119,138,159,181,204,229,255,283,

%T 312,342,374,407,442,478,515,554,595,636,679,724,770,817,866,916,968,

%U 1021,1075,1131,1189,1247,1307,1369,1432,1496,1562,1629,1698,1768,1839,1912

%N a(n)^2 is the greatest square not exceeding A000217(n^2).

%H Michael De Vlieger, <a href="/A373329/b373329.txt">Table of n, a(n) for n = 0..10000</a>

%F a(n) = A061288(n^2). - _Alois P. Heinz_, Jun 01 2024

%p a:= n-> floor(sqrt((t-> t*(t+1)/2)(n^2))):

%p seq(a(n), n=0..52);  # _Alois P. Heinz_, Jun 01 2024

%t Array[Floor@ Sqrt[(#^4 + #^2)/2] &, 53, 0] (* _Michael De Vlieger_, Jun 02 2024 *)

%o (PARI) a(n) = sqrtint((n^4+n^2)/2)

%Y Cf. A000217, A000290, A001109 (subsequence), A001110, A001333, A037270, A061288.

%K nonn

%O 0,3

%A _Hugo Pfoertner_, Jun 01 2024