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A232848
Prime(k), where k divides Sum_{i=1..k} prime(i)^15.
0
2, 59, 97, 127, 12517, 54581, 83921, 89273, 1396411, 2562719, 4952183, 29201281, 35562101, 47567557, 111213143, 184201627, 1172476337, 7309217299, 287609314877, 5173838081669, 408907258717171, 1357729730868191, 66413899001789557
OFFSET
1,1
FORMULA
a(n) = prime(A131275(n)).
EXAMPLE
a(2) = 59, because 59 is the 17th prime and the sum of the first 17 primes^15 = 455708280934100194626604550 when divided by 17 equals 26806369466711776154506150 which is an integer.
MATHEMATICA
t = {}; sm = 0; Do[sm = sm + Prime[n]^15; If[Mod[sm, n] == 0, AppendTo[t, Prime[n]]], {n, 100000}]; t (* Derived from A217599 *)
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
(PARI) S=n=0; forprime(p=1, , (S+=p^15)%n++||print1(p", ")) \\ M. F. Hasler, Dec 01 2013
CROSSREFS
Cf. A085450 (smallest m > 1 such that m divides Sum_{k=1..m} prime(k)^n), A131275.
Sequence in context: A195325 A195329 A197185 * A215393 A141869 A329551
KEYWORD
nonn,more
AUTHOR
Robert Price, Dec 09 2013
EXTENSIONS
a(20) from Karl-Heinz Hofmann, Feb 17 2021
a(21) from Bruce Garner, Apr 30 2021
a(22) from Bruce Garner, Jan 07 2022
a(23) from Paul W. Dyson, Apr 18 2024
STATUS
approved