OFFSET
1,1
COMMENTS
a(49) > 661876608760109. - Bruce Garner, Jun 02 2021
LINKS
Bruce Garner, Table of n, a(n) for n = 1..48 (first 43 terms from Robert Price)
EXAMPLE
a(3) = 7, because 7 is the 4th prime and the sum of the first 4 primes^15+1 = 4778093469744 when divided by 4 equals 1194523367436 which is an integer.
MATHEMATICA
t = {}; sm = 1; Do[sm = sm + Prime[n]^15; If[Mod[sm, n] == 0, AppendTo[t, Prime[n]]], {n, 100000}]; t (* Derived from A217599 *)
nn=7000000; With[{pr15=Accumulate[Prime[Range[nn]]^15]+1}, Prime[ #]&/@ Select[ Range[nn], Divisible[pr15[[#]], #]&]] (* This program will generate the first 28 terms of the sequence. To generate an additional 6 terms terms, nn would have to equal 659 million, and the program would take a long time to run. *) (* Harvey P. Dale, May 01 2014 *)
PROG
(PARI) is(n)=if(!isprime(n), return(0)); my(t=primepi(n), s); forprime(p=2, n, s+=Mod(p, t)^15); 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 09 2013
STATUS
approved