Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #11 Oct 30 2019 17:38:10
%S 1,2,4,5,9,14,16,17,21,30,35,36,40,41,55,60,76,93,102,103,108,129,131,
%T 132,136,141,143,152,166,167,197,198,214,215,232,267,303,304,306,307,
%U 347,388,409,410,414,423,425,426,442,443,448,465,469,470,479,534,548
%N a(0)=1. For n>=1, a(n) = a(n-1) + (largest divisor of n which occurs among the earlier terms of the sequence).
%t f[l_List] := Append[l, l[[ -1]] + Max @@ Intersection[l, Divisors[Length[l]]]];Nest[f, {1}, 60] (* _Ray Chandler_, Feb 19 2007 *)
%Y Cf. A123090.
%K nonn
%O 0,2
%A _Leroy Quet_, Feb 15 2007
%E Extended by _Ray Chandler_, Feb 19 2007