A013932 Integers that are squarefree and also the sum of first k squarefrees for some k.

1, 3, 6, 11, 17, 34, 58, 87, 123, 166, 215, 274, 305, 407, 482, 521, 562, 647, 791, 899, 1073, 1261, 1327, 1394, 1463, 1533, 1677, 1751, 1906, 1985, 2067, 2235, 2321, 2497, 2681, 2870, 2967, 3170, 3273, 3378, 3810, 3921, 4034, 4381, 4622, 4745, 5001, 5131, 5262

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

Select[Accumulate[Select[Range[150], SquareFreeQ]], SquareFreeQ] (* Harvey P. Dale, Jul 27 2011 *)

Prog

(PARI) lista(nn) = {my(s=0); for(k=1, nn, if(issquarefree(k)==1, s+=k; if(issquarefree(s)==1, print1(s, ", ")))); } \\ Jinyuan Wang, Feb 26 2020

Crossrefs

Cf. A005117, A013930, A013931, A173143.

Sequence in context: A279032 A124454 A335631 * A302550 A310117 A161864

Adjacent sequences: A013929 A013930 A013931 * A013933 A013934 A013935

Keyword

nonn

Author

Henri Lifchitz

Extensions

More terms from Jinyuan Wang, Feb 26 2020

Status

approved