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.

Showing 1-1 of 1 results.

A342364 The primes associated with A239727.

Original entry on oeis.org

3, 17, 73, 191, 709, 1289, 3181, 5449, 7681, 17477, 33889, 87961, 437389, 2290573, 7160227, 10429681, 19196227, 24504049, 47577857, 70513979, 82605937, 156671243, 271785793, 328939937, 568119509, 1125978241, 1534657963, 1710749497, 4936728373, 7647104183
Offset: 1

Views

Author

Jianing Song, Mar 09 2021

Keywords

Examples

			The smallest prime of the form 2*A239727(3)*k + 1 = 24*k+1 is 73, hence a(3) = 73.
The smallest prime of the form 2*A239727(4)*k + 1 = 38*k+1 is 191, hence a(4) = 191.
		

Crossrefs

Programs

  • PARI
    A016014(n)=my(k); while(!isprime(2*n*k+++1), ); k
    r=0; for(n=1, 1e8, t=A016014(n); if(t>r, r=t; print1(2*n*r+1", "))) \\ based on the program of A239727

Formula

a(n) = 2*A239727(n)*A239746(n) + 1.
Showing 1-1 of 1 results.