A369185 Numbers k such that Omega(k) = 1 + Omega(k+1) = 2 + Omega(k+2).

45, 104, 105, 165, 260, 261, 344, 345, 357, 440, 465, 476, 477, 561, 776, 860, 861, 884, 885, 981, 1016, 1017, 1112, 1160, 1185, 1269, 1281, 1395, 1424, 1544, 1572, 1624, 1644, 1652, 1683, 1808, 1812, 1827, 1905, 1917, 1989, 2037, 2060, 2061, 2097, 2145, 2277, 2444, 2445, 2805, 2817, 2852, 2877

Offset

1,1

Comments

Numbers k such that both k and k+1 are in A369139.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(4) = 165 is a term because 165 = 3 * 5 * 11 has 3 prime factors (counted with multiplicity), 166 = 2 * 83 has 2 and 167 (which is prime) has 1.

Maple

N:= 10^4: # for terms <= N
V:= map(numtheory:-bigomega, [$1..N+2]):
select(t -> V[t] = 1 + V[t+1] and V[t] = 2 + V[t+2], [$1..N]);

Crossrefs

Cf. A001222, A369139. Includes x-2 for x in A201147.

Sequence in context: A350422 A350332 A247887 * A063069 A067828 A144552

Adjacent sequences: A369182 A369183 A369184 * A369186 A369187 A369188

Keyword

nonn

Author

Zak Seidov and Robert Israel, Jan 15 2024

Status

approved