cp's OEIS Frontend

A073856 a(1) = 1, then the smallest n-th power not included earlier such that each partial sum is a prime.

%I A073856 #6 Sep 27 2024 23:01:34
%S A073856 1,4,8,16,32,4096,279936,656100000000,19683000000000,3656158440062976,
%T A073856 36028797018963968,417030640378345864542952820736,6502111422497947648,
%U A073856 329539482806454424642350193846115106816,24066838317339048730709164032
%N A073856 a(1) = 1, then the smallest n-th power not included earlier such that each partial sum is a prime.
%H A073856 Robert Israel, <a href="/A073856/b073856.txt">Table of n, a(n) for n = 1..239</a>
%p A073856 R:= 1: S:= {1}: s:= 1:
%p A073856 for n from 2 to 20 do
%p A073856   for k from 2 do
%p A073856     v:= k^n;
%p A073856     if member(v,S) then next fi;
%p A073856     if isprime(s+v) then R:= R,v; S:= S union {v}; s:= s+v;   fi;
%p A073856 od od:
%p A073856 R; # _Robert Israel_, Sep 27 2024
%Y A073856 Cf. A073857.
%K A073856 nonn
%O A073856 1,2
%A A073856 _Amarnath Murthy_, Aug 15 2002
%E A073856 More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 24 2003