A070805 a(1) = 2; a(n) = largest prime not exceeding the sum of all previous terms.

2, 3, 5, 7, 17, 31, 61, 113, 239, 467, 941, 1879, 3761, 7523, 15031, 30071, 60149, 120299, 240599, 481181, 962363, 1924721, 3849437, 7698893, 15397783, 30795571, 61591147, 123182281, 246364571, 492729101, 985458239, 1970916449

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Mathematica

tb[0]={} tb[x_] := Union[tb[x-1], m[x]] m[x_] := {Prime[PrimePi[Apply[Plus, tb[x-1]]]]} Union[Delete[Flatten[Table[m[w], {w, 1, 20}]], 1], {2}]
nxt[{t_, p_}]:=Module[{c=If[PrimeQ[t], t, NextPrime[t, -1]]}, {t+c, c}]; Join[ {2}, NestList[nxt, {5, 3}, 40][[All, 2]]] (* Harvey P. Dale, Jun 21 2020 *)

Crossrefs

Cf. A070218.

Sequence in context: A048418 A074788 A262833 * A255161 A103385 A103389

Adjacent sequences: A070802 A070803 A070804 * A070806 A070807 A070808

Keyword

nonn

Author

Labos Elemer, May 08 2002

Status

approved