A120610 Sum of previous term and preceding non-divisors.
2, 3, 5, 10, 13, 33, 63, 126, 187, 442, 869, 1753, 3506, 5257, 12269, 24538, 36805, 85876, 171755, 343507, 687019, 1374038, 2061055, 4809126, 9618252, 14427378, 28854567, 62518388, 125036840, 250073665, 500147342, 1000294687, 2000589376
Offset: 1
Keywords
Links
- Michael De Vlieger, Table of n, a(n) for n = 1..3428
Crossrefs
Cf. A120611.
Programs
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Mathematica
s={2,3};Do[sum=s[[-1]];Do[If[!Divisible[s[[-1]],s[[j]]],sum=sum+s[[j]] ],{j,k-1}];AppendTo[s,sum] ,{k,2,32}];s (* James C. McMahon, Oct 07 2024 *)
Formula
a(1) = 2, a(2) = 3, for n>=2, a(n+1) = a(n) + sum_{1<=k