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%I #30 Oct 19 2017 03:14:19
%S 5,13,229,1093,2029,3253,13693,21613,59053,65029,91813,140629,178933,
%T 199813,205213,227533,328333,567013,700573,804613,815413,1071229,
%U 2241013,3629029,4223029,4347229,4809253,5212093,5919493,6185173
%N Greater of twin primes of the form x^2+2, x^2+4.
%C Except for the first term, all a(n)=13 (mod 72) with x=3 (mod 6). The lesser of the twin prime pair is given by A253639, the x-values in A086381. - _M. F. Hasler_, Jan 18 2015
%H M. F. Hasler, <a href="/A085554/b085554.txt">Table of n, a(n) for n = 1..3044</a> (all terms below 10^12).
%F A085554 = A087475 o A086381 = A020725^2 o A253639, i.e., a(n) = A087475(A086381(n)) = A253639(n)+2. - _M. F. Hasler_, Jan 18 2015
%t Transpose[Select[Table[x^2+{2,4},{x,5000}],AllTrue[#,PrimeQ]&]][[2]] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Jan 15 2015 *)
%o (PARI) is_A086381(x)=ispseudoprime(x^2+2)&&ispseudoprime(x^2+4) \\ or is_A067201(x)&&is_A007591(x)
%o A085554 = apply(A087475,select(is_A086381,vector(9999,n,n))) \\ A087475=x->x^2+4.
%o write(f="b085554.txt",c=1," 5"); forstep(x=3,1e6,6,is_A086381(x)&&write(f,c++" "x^2+4))
%o \\ _M. F. Hasler_, Jan 18 2015
%Y Cf. A085553, A086381, A087475, A059100.
%K easy,nonn
%O 1,1
%A _Cino Hilliard_, Jul 04 2003
%E Edited by _Don Reble_, May 03 2006
%E Definition corrected by _Harvey P. Dale_ and _Franklin T. Adams-Watters_, Jan 15 2015
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