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A144975 Centered heptagonal twin prime numbers. 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

Wikipedia, Centered heptagonal twin prime numbers

EXAMPLE

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).

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

PROG

(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

CROSSREFS

Cf. A001097, A069099.

Sequence in context: A087765 A141971 A144974 * A087699 A054807 A285017

Adjacent sequences:  A144972 A144973 A144974 * A144976 A144977 A144978

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Sep 27 2008

STATUS

approved

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Last modified March 5 09:57 EST 2021. Contains 341818 sequences. (Running on oeis4.)