A262783 Terms of A173143 (partial sums of squarefree numbers) that are square.

1, 144, 6084, 33856, 37636, 6310144, 10150596, 14668900, 20007729, 3292234884, 39600602001, 92437853419755481, 2849708967414258609

Offset: 1

Author

Michel Marcus, Oct 01 2015

Keywords

• nonn
• more

Comments

Intersection of A000290 and A173143.

a(12) > 10^15. - Jon E. Schoenfield, Oct 11 2015

a(14) > 3*10^21. The first 13 terms are the sums of the first 1, 21, 141, 331, 354, 4555, 5785, 6949, 8110, 104070, 360930, 551460217, 3061889301 squarefree numbers. - Giovanni Resta, Aug 19 2018

Examples

			The sum of the first 14 squarefree integers is 1 + 2 + 3 + 5 + 6 + 7 + 10 + 11 + 13 + 14 + 15 + 17 + 19 + 21 = 144, a square.
		

Crossrefs

Cf. A000290, A005117, A173143.

Programs

PARI

lista(nn) = {s = 0; i = 0; for (n=1, nn, if (issquarefree(n), i++; s += n; if (issquare(s), print1(s, ", "));););}

Extensions

a(12)-a(13) from Giovanni Resta, Aug 19 2018