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
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
Select[Accumulate[Select[Range[150],SquareFreeQ]],SquareFreeQ] (* Harvey P. Dale, Jul 27 2011 *)
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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
Formula
Extensions
More terms from Jinyuan Wang, Feb 26 2020