

A126194


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.


1



7, 19, 31, 43, 61, 73, 109, 139, 181, 193, 199, 229, 241, 271, 283, 313, 349, 421, 433, 463, 571, 601, 619, 643, 661, 811, 823, 829, 859, 883, 1021, 1051, 1063, 1093, 1153, 1231, 1279, 1291, 1303, 1321, 1429, 1453, 1483, 1489, 1609, 1621, 1669, 1699, 1723
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OFFSET

1,1


COMMENTS

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


LINKS

Table of n, a(n) for n=1..49.


EXAMPLE

7 = 2^2+3 and 19 = 2^4+3; 7 and 19 are greater of twin primes;
31 = 4^2+15 and 271 = 4^4+15; 31 and 271 are greater of twin primes.


PROG

(PARI) {m=42; v=[]; for(k=2, m, for(s=1, (m+1)^21, if((p=k^2+s)<m^2&&isprime(p)&&isprime(p2)&&(q=k^4+s)>p&&isprime(q)&&isprime(q2), v=concat(v, p)))); v=listsort(List(v), 1); for(j=1, #v, print1(v[j], ", "))} /* Klaus Brockhaus, Mar 09 2007 */


CROSSREFS

Cf. A006512, A126769, A126193.
Sequence in context: A079740 A030549 A017605 * A068229 A071696 A216530
Adjacent sequences: A126191 A126192 A126193 * A126195 A126196 A126197


KEYWORD

easy,nonn


AUTHOR

Tomas Xordan, Mar 07 2007


EXTENSIONS

Edited and corrected by Klaus Brockhaus, Mar 09 2007


STATUS

approved



