A144975 Centered heptagonal twin prime numbers.

43, 71, 197, 463, 1933, 5741, 8233, 9283, 11173, 14561, 34651, 41203, 57793, 68111, 84631, 104147, 139301, 168631, 207523, 244861, 307693, 333103, 357281, 415381, 465011, 475273, 506731, 592663, 595547, 607153, 729373, 742211, 781397, 876751

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Sep 27 2008

Keywords

• nonn

Examples

			43 is a term since it is centered heptagonal and the greater member of the twin primes pair (41, 43).
71 is a term since it is centered heptagonal and the lesser member of the twin primes pair (71, 73).
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• Wikipedia, Centered heptagonal twin prime numbers

Crossrefs

Cf. A001097, A069099.

Programs

Magma

[a:k in [1..510]|IsPrime(a) and (IsPrime(a-2) or IsPrime(a+2)) where a is (7*k^2-7*k+2) div 2]; // Marius A. Burtea, Jan 30 2020

Mathematica

TwinPrimeQ[n_]:=If[PrimeQ[n],If[PrimeQ[n-2]||PrimeQ[n+2],True,False],False](*TwinPrimeQ*) lst={};Do[p=(7*n^2-7*n+2)/2;If[TwinPrimeQ[p],AppendTo[lst,p]],{n,2*6!}];lst