OFFSET
1,1
COMMENTS
Odd n such that sum(k=1,n-1,floor(k^3/n)) is different from (1/4)*(n-2)*(n^2-1) (equality holds for n prime as well as for "1" union "A024556" ). - Benoit Cloitre, Dec 08 2002
Odd nonsquarefree numbers, odd terms of A013929. - Zak Seidov, Aug 16 2006
The asymptotic density of this sequence is 1/2 - 4/Pi^2 = 0.094715... - Amiram Eldar, Nov 21 2020
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Prime Sums.
MATHEMATICA
Select[Range[1, 500, 2], !SquareFreeQ[#] &] (* Amiram Eldar, Nov 21 2020 *)
PROG
(PARI) lista(nn) = {forstep(n=1, nn, 2, if (! issquarefree(n), print1(n, ", "))); } \\ Michel Marcus, Jun 06 2014
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, Mar 28 2000
STATUS
approved