A333019 Numbers k such that both k and k + 2 are totient numbers (A002202).

2, 4, 6, 8, 10, 16, 18, 20, 22, 28, 30, 40, 42, 44, 46, 52, 54, 56, 58, 64, 70, 78, 80, 82, 100, 102, 104, 106, 108, 110, 126, 128, 130, 136, 138, 148, 160, 162, 164, 166, 176, 178, 190, 196, 198, 208, 210, 220, 222, 224, 226, 238, 250, 260, 262, 268, 270, 280

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Wikipedia, Totient numbers.

Example

2 is a term since both 2 and 4 are totient numbers.

Prog

(PARI) for(k = 1, 150, if(istotient(2*k) && istotient(2*k+2), print1(2*k, ", ")))

Crossrefs

Cf. A000010, A002202, A005277, A063512, A083533, A333020, A333021, A333022, A333023, A333024.

Sequence in context: A345986 A226809 A161562 * A102470 A057195 A088007

Adjacent sequences: A333016 A333017 A333018 * A333020 A333021 A333022

Keyword

nonn

Author

Amiram Eldar, Mar 05 2020

Status

approved