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A108604 Squares of the form prime(k)*prime(k+1) + 2*prime(k+1). 6

%I #18 Jan 28 2024 18:10:23

%S 25,49,169,361,961,1849,3721,5329,10609,11881,19321,22801,32761,37249,

%T 39601,52441,58081,73441,80089,97969,121801,177241,187489,214369,

%U 273529,326041,361201,383161,413449,436921,657721,677329,687241,737881,779689

%N Squares of the form prime(k)*prime(k+1) + 2*prime(k+1).

%C Squares of greater of twin primes.

%H Winston de Greef, <a href="/A108604/b108604.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A006512(n)^2.

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

%t Select[Sqrt/@Table[Prime[k]*Prime[k+1]+2Prime[k+1],{k,160}],IntegerQ]^2 (* _James C. McMahon_, Jan 27 2024 *)

%Y Cf. A006512, A108570.

%K easy,nonn

%O 1,1

%A _Giovanni Teofilatto_, Jul 06 2005

%E Corrected and extended by _Ray Chandler_, Jul 10 2005

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Last modified April 25 03:15 EDT 2024. Contains 371964 sequences. (Running on oeis4.)