A333021 Starts of runs of 4 consecutive even numbers that are all totient numbers (A002202).

2, 4, 6, 16, 18, 40, 42, 52, 54, 78, 100, 102, 104, 106, 126, 160, 162, 220, 222, 342, 378, 438, 460, 462, 498, 500, 502, 856, 858, 880, 882, 1086, 1276, 1278, 1300, 1422, 1480, 1482, 1566, 1660, 1662, 1804, 1806, 1996, 2058, 2200, 2202, 2236, 2238, 3016, 3018

Offset

1,1

Links

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

Wikipedia, Totient numbers.

Example

2 is a term since 2, 4, 6 and 8 are all totient numbers.

Prog

(PARI) m = 4; v = vector(m); for(k=1, m, v[k] = istotient(2*k)); for(k = m+1, 1500, if(Set(v) == [1], print1(2*(k-m), ", ")); v = concat(v[2..m], istotient(2*k)))

Crossrefs

Cf. A000010, A002202, A005277, A063512, A083533, A333019, A333020, A333022, A333023, A333024.

Sequence in context: A096174 A096173 A287681 * A114874 A100361 A259939

Adjacent sequences: A333018 A333019 A333020 * A333022 A333023 A333024

Keyword

nonn

Author

Amiram Eldar, Mar 05 2020

Status

approved