A334142 Indices of twin primes.

2, 3, 4, 5, 6, 7, 8, 10, 11, 13, 14, 17, 18, 20, 21, 26, 27, 28, 29, 33, 34, 35, 36, 41, 42, 43, 44, 45, 46, 49, 50, 52, 53, 57, 58, 60, 61, 64, 65, 69, 70, 81, 82, 83, 84, 89, 90, 98, 99, 104, 105, 109, 110, 113, 114, 116, 117, 120, 121, 140, 141, 142, 143, 144, 145, 148, 149

Offset

1,1

Links

Table of n, a(n) for n=1..67.

Eric Weisstein's World of Mathematics, Twin Primes

Formula

a(n) = A000720(A001097(n)).

Set union of A029707 and A107770.

Maple

q:= n-> (p-> isprime(p-2) or isprime(p+2))(ithprime(n)):
select(q, [$1..150])[];  # Alois P. Heinz, Apr 15 2020

Crossrefs

Cf. A000720, A001097, A029707, A107770.

Sequence in context: A049810 A132018 A369003 * A044919 A011871 A229769

Adjacent sequences: A334139 A334140 A334141 * A334143 A334144 A334145

Keyword

nonn

Author

Ilya Gutkovskiy, Apr 15 2020

Status

approved