A321496 Numbers k such that k and k+1 have at least 6 but not both exactly 6 distinct prime factors.

58524465, 64822394, 130578734, 133595384, 143489709, 153124685, 155197965, 156532089, 157955720, 159653409, 165706904, 169075829, 170118234, 175458920, 184867605, 188377475, 193042394, 194236679, 195719810, 199150665, 202429590, 208727805, 209801514, 211588454

Offset: 1

Author

M. F. Hasler, Nov 12 2018

Keywords

• nonn

Comments

Complement of A273879 (k and k+1 have exactly 6 distinct prime factors) in A321506 (k and k+1 have at least 6 distinct prime factors).

Crossrefs

Cf. A273879, A321506; A321495 (analog for 5 factors).

Programs

Mathematica

aQ[n_]:=Module[{v={PrimeNu[n], PrimeNu[n+1]}}, Min[v]>5 && v!={6, 6}]; Select[Range[10^9], aQ] (* Amiram Eldar, Nov 12 2018 *)

PARI

is(n)=omega(n)>5&&omega(n+1)>5&&(omega(n)>6||omega(n+1)>6)

Formula

A321506 \ A273879.

Extensions

More terms from Amiram Eldar, Nov 12 2018