OFFSET
1,1
COMMENTS
a(280) > 1701962315686097. - Bruce Garner, Jun 05 2021
LINKS
Bruce Garner, Table of n, a(n) for n = 1..279 (terms 1..215 from Robert Price)
EXAMPLE
a(6) = 13, because 13 is the 6th prime and the sum of the first 6 primes^4+1 = 46326 when divided by 6 equals 7721 which is an integer.
MATHEMATICA
t = {}; sm = 1; Do[sm = sm + Prime[n]^4; If[Mod[sm, n] == 0, AppendTo[t, Prime[n]]], {n, 100000}]; t (* Derived from A217599 *)
Module[{nn=1400, t}, t=Accumulate[Prime[Range[nn]]^4]+1; Prime[#]&/@ Transpose[Select[Thread[{Range[nn], t}], IntegerQ[#[[2]]/#[[1]]]&]][[1]]](* Harvey P. Dale, Sep 06 2015 *)
PROG
(PARI) is(n)=if(!isprime(n), return(0)); my(t=primepi(n), s); forprime(p=2, n, s+=Mod(p, t)^4); s==0 \\ Charles R Greathouse IV, Nov 30 2013
CROSSREFS
Cf. A085450 (smallest m > 1 such that m divides Sum_{k=1..m} prime(k)^n).
KEYWORD
nonn
AUTHOR
Robert Price, Dec 17 2013
STATUS
approved