OFFSET
1,1
COMMENTS
All square roots of twin prime sums in this sequence (see A152786) are multiples of 6.
Digital roots of all pairs in this sequence are {8,1}.
Twin primes of the form 18n^2 +- 1. - Charles R Greathouse IV, Aug 26 2014
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
FORMULA
a(2*n) = a(2*n-1) + 2, a(2*n+1) = A069496(n).
EXAMPLE
17+19 = 36, square root of 36 = 6; 71+73 = 144, square root of 144 = 12.
MATHEMATICA
t = {}; Do[ps = {2 n^2 - 1, 2 n^2 + 1}; If[PrimeQ[ps[[1]]] && PrimeQ[ps[[2]]], AppendTo[t, ps]], {n, 1000}]; Flatten[t] (* T. D. Noe, Dec 03 2013 *)
PROG
(PARI) for(n=1, 1e3, if(isprime(t=18*n^2-1) && isprime(t+2), print1(t", "t+2", "))) \\ Charles R Greathouse IV, Aug 26 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Gary Croft, Dec 01 2013
STATUS
approved