A120875 Product of twin primes minus 1.

14, 34, 142, 322, 898, 1762, 3598, 5182, 10402, 11662, 19042, 22498, 32398, 36862, 39202, 51982, 57598, 72898, 79522, 97342, 121102, 176398, 186622, 213442, 272482, 324898, 359998, 381922, 412162, 435598, 656098, 675682, 685582, 736162

Offset

1,1

Comments

This sequence is a subsequence of A023515.

Links

Jason Kimberley (using T. Noe's b037074), Table of n, a(n) for n = 1..10000

Formula

a(n) = A037074(n)-1 = (A014574(n))^2 -2 = A075369(n)-2.

a(n) = 2*A120876(n). - Jason Kimberley, Oct 23 2015

a(n) = 36*A002822(n-1)^2-2, for n>1. - Jason Kimberley, Oct 23 2015

a(n) = A023515(A107770(n)). - Jason Kimberley, Oct 23 2015

Mathematica

Times[#, # + 2] - 1 & /@ Select[Prime@ Range@ 150, PrimeQ[# + 2] &] (* Michael De Vlieger, Oct 23 2015 *)

Prog

(PARI) for(n=1, 200, if(prime(n+1)-prime(n)==2, print1(prime(n)*prime(n+1)-1", "))) \\ Altug Alkan, Oct 23 2015

Crossrefs

Cf. A002822, A023515, A037074, A075369, A120876.

Sequence in context: A329062 A072566 A039449 * A103533 A269663 A046425

Adjacent sequences: A120872 A120873 A120874 * A120876 A120877 A120878

Keyword

nonn

Author

Lekraj Beedassy, Jul 09 2006

Status

approved