A108570 Squares of lesser of twin primes.

9, 25, 121, 289, 841, 1681, 3481, 5041, 10201, 11449, 18769, 22201, 32041, 36481, 38809, 51529, 57121, 72361, 78961, 96721, 120409, 175561, 185761, 212521, 271441, 323761, 358801, 380689, 410881, 434281, 654481, 674041, 683929, 734449, 776161

Offset

1,1

Comments

Squares of the form prime(n)*prime(n+1) - 2*prime(n).

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Maple

ZL:=[]:for p from 1 to 950 do if (isprime(p) and isprime(p+2)) then ZL:=[op(ZL), (p^2)]; fi; od; print(ZL); # Zerinvary Lajos, Mar 08 2007

Mathematica

Select[First[#]Last[#]-2First[#]&/@Partition[Prime[Range[500]], 2, 1], IntegerQ[ Sqrt[#]]&] (* Harvey P. Dale, May 24 2011 *)

Prog

(PARI) p=2; forprime(q=3, , if(q-p==2, print1(p^2", ")); p=q) \\ Charles R Greathouse IV, Dec 16 2019
(Magma) [p^2 : p in PrimesUpTo(1100)| IsPrime(p+2)]; // Vincenzo Librandi, Dec 23 2019

Crossrefs

Subsequence of A330477.

Cf. A001359, A108604.

Sequence in context: A193644 A083100 A084058 * A092769 A263951 A139818

Adjacent sequences: A108567 A108568 A108569 * A108571 A108572 A108573

Keyword

easy,nonn

Author

Giovanni Teofilatto, Jul 05 2005

Extensions

Extended by Ray Chandler, Jul 10 2005

Name and comment swapped by Charles R Greathouse IV, Dec 16 2019

Status

approved