A126194 - OEIS

%I #3 Sep 24 2013 09:24:38

%S 7,19,31,43,61,73,109,139,181,193,199,229,241,271,283,313,349,421,433,

%T 463,571,601,619,643,661,811,823,829,859,883,1021,1051,1063,1093,1153,

%U 1231,1279,1291,1303,1321,1429,1453,1483,1489,1609,1621,1669,1699,1723

%N Greater of twin primes (A006512) of the form p = k^2+s such that q = k^4+s is also a greater of twin primes, q > p.

%C p = q-k^4+k^2 where p and q are greater of twin primes and p < q.

%e 7 = 2^2+3 and 19 = 2^4+3; 7 and 19 are greater of twin primes;

%e 31 = 4^2+15 and 271 = 4^4+15; 31 and 271 are greater of twin primes.

%o (PARI) {m=42; v=[]; for(k=2, m, for(s=1, (m+1)^2-1, if((p=k^2+s)<m^2&&isprime(p)&&isprime(p-2)&&(q=k^4+s)>p&&isprime(q)&&isprime(q-2), v=concat(v,p)))); v=listsort(List(v), 1); for(j=1, #v, print1(v[j], ","))} /* Klaus Brockhaus, Mar 09 2007 */

%Y Cf. A006512, A126769, A126193.

%K easy,nonn

%O 1,1

%A _Tomas Xordan_, Mar 07 2007

%E Edited and corrected by _Klaus Brockhaus_, Mar 09 2007