cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A233555 Prime(m), where m is such that (Sum_{i=1..m} prime(i)^17) / m is an integer.

Original entry on oeis.org

2, 5724469, 10534369, 16784723, 33330911, 189781037, 8418091991, 58605633953, 109388266843, 448366797199, 1056238372873, 24603683667221, 86982253895059, 100316149840769, 164029709175817, 542295448805641, 685217940914237, 1701962315686097, 23064173255594491
Offset: 1

Views

Author

Robert Price, Dec 12 2013

Keywords

Comments

a(18) > 1005368767096627. - Bruce Garner, Aug 30 2021
a(19) > 1701962315686097. - Bruce Garner, Jan 07 2022

Examples

			a(1) = 2, because 2 is the 1st prime and the sum of the first 1 primes^17 = 131072 when divided by 1 equals 131072 which is an integer.
		

Crossrefs

Cf. A085450 (smallest m > 1 that divide Sum_{k=1..m} prime(k)^n).

Programs

  • Mathematica
    t = {}; sm = 0; Do[sm = sm + Prime[n]^17; If[Mod[sm, n] == 0, AppendTo[t, Prime[n]]], {n, 100000}]; t (* Derived from A217599 *)
  • PARI
    is(n)=if(!isprime(n),return(0)); my(t=primepi(n),s); forprime(p=2,n,s+=Mod(p,t)^17); s==0 \\ Charles R Greathouse IV, Nov 30 2013
    
  • PARI
    S=n=0;forprime(p=1,,(S+=p^17)%n++||print1(p",")) \\ M. F. Hasler, Dec 01 2013

Formula

a(n) = prime(A131277(n)).

Extensions

a(12) from Bruce Garner, Mar 02 2021
a(13) from Bruce Garner, Mar 17 2021
a(14) from Bruce Garner, Mar 30 2021
a(15) from Bruce Garner, Apr 14 2021
a(16) from Bruce Garner, Jun 30 2021
a(17) from Bruce Garner, Aug 30 2021
a(18) from Bruce Garner, Jan 07 2022
a(19) from Paul W. Dyson, Sep 15 2023