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.

A343123 Primes p such that the sum of A001414(k) for k strictly between p and the following prime is a proper prime power (a term of A246547).

Original entry on oeis.org

3, 13, 17, 19, 239, 269, 457, 751, 1091, 1319, 1871, 2129, 2141, 2341, 2549, 2683, 2969, 3167, 3359, 3671, 3821, 4091, 4799, 5437, 5843, 6299, 6551, 6779, 7559, 8387, 8999, 9239, 9419, 10529, 11057, 11717, 11777, 12071, 13309, 13901, 17027, 17203, 18047, 18311, 18521, 21139, 23831, 26249, 26861
Offset: 1

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Author

J. M. Bergot and Robert Israel, Apr 05 2021

Keywords

Comments

Primes prime(k) such that Sum_{prime(k) < j < prime(k+1)} A001414(j) is in A246547.

Examples

			a(4) = 19 is a term because 19 and 23 are consecutive primes with Sum_{19 < j < 23} A001414(j) = 9+10+13 = 32 = 2^5.
		

Crossrefs

Programs

  • Maple
    spf:= proc(n) local t; add(t[1]*t[2],t=ifactors(n)[2]) end proc:
    R:= NULL: count:= 0: p:= 2:
    while count < 100 do
      q:= p; p:= nextprime(p);
      L:= ifactors(add(spf(i),i=q+1..p-1))[2];
      if nops(L) = 1 and L[1][2]>1 then
        count:= count+1; R:= R, q;
      fi
    od:
    R;