A095971 If p(k) is the k-th prime, then the n-th set of 4 consecutive cousin prime pairs starts at p(a(n)).

25, 147, 149, 1828, 1866, 18814, 20033, 26397, 57344, 63654, 71722, 72982, 76928, 85072, 99739, 110985, 122244, 136645, 145805, 166884, 183130, 204206, 244875, 246292, 256139, 258721, 258723, 263243, 296747, 296749, 299538, 336778, 356245, 396811, 425385, 449918, 455824, 467844, 478051, 494380

Offset

1,1

Links

Table of n, a(n) for n=1..40.

Example

a(1)=25: p(25)=97 and p(26)=101, the first cousin prime pair; p(27)=103 and p(28)=107, the second cousin prime pair; p(29)=109 and p(30)=113, the third cousin prime pair; p(31)=127 and p(32)=131, the fourth cousin prime pair.

Maple

P:= select(isprime, [2, seq(i, i=3..10^7, 2)]):
G:= P[2..-1]-P[1..-2]:
select(t -> G[t] =4 and G[t+2] = 4 and G[t+4] = 4 and G[t+6] = 4, [$1..nops(G)-6]); # Robert Israel, May 15 2025

Crossrefs

Sequence in context: A123014 A392863 A366167 * A147421 A147083 A198030

Adjacent sequences: A095968 A095969 A095970 * A095972 A095973 A095974

Keyword

nonn

Author

Ray G. Opao, Jul 15 2004

Extensions

More terms from Robert Israel, May 15 2025

Status

approved