OFFSET
1,1
COMMENTS
The first 18 terms are the sums of the first 1, 5, 27, 95, 110, 150, 135833, 265758, 360459, 427441, 2542860, 16883814, 137228168, 195143291, 2283242905, 19745293160, 24246846494, 92558706480 nonsquarefree numbers.
a(19) > 2*10^22. - Giovanni Resta, Nov 17 2019
EXAMPLE
49 is a term because sum of first five nonsquarefree numbers is a square 4 + 8 + 9 + 12 + 16 = 49.
MATHEMATICA
p=0; Do[If[!SquareFreeQ[n], p=p+n; If[IntegerQ[p^(1/2)], Print[p]]], {n, 1, 10^8}]
PROG
(PARI) lista(nn) = {my(s=0); for(k=1, nn, if(omega(k)!=bigomega(k), s+=k; if(issquare(s), print1(s, ", ")))); } \\ Jinyuan Wang, Nov 17 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Metin Sariyar, Nov 15 2019
EXTENSIONS
a(13)-a(18) from Giovanni Resta, Nov 17 2019
STATUS
approved