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A321497 Numbers k such that both k and k+1 have at least 7 distinct prime factors and at least one has more than 7 distinct prime factors. 4

%I #9 Nov 14 2018 13:42:35

%S 5163068910,5327923964,6564937379,6880516929,7122669554,8567026545,

%T 8814635115,9533531370,9611079114,10245081314,10246336814,10697507414,

%U 10783550414,10796559410,11260076190,11458770609,11992960265,12043540145,12172828590,12745759740,12850545785,12946979220

%N Numbers k such that both k and k+1 have at least 7 distinct prime factors and at least one has more than 7 distinct prime factors.

%C Terms of A321489 (k and k+1 have at least 7 distinct prime factors) which don't satisfy the definition with "exactly 7".

%t aQ[n_]:=Module[{v={PrimeNu[n], PrimeNu[n+1]}}, Min[v]>6 && v!={7, 7}]; Select[Range[10^10], aQ]

%o (PARI) is(n)=omega(n)>6&&omega(n+1)>6&&(omega(n)>7||omega(n+1)>7)

%Y Cf. A321489, A321503, A321504, A321505, A321506, A321493, A321494, A321495, A321496 (analog for 3 .. 6 factors).

%K nonn

%O 1,1

%A _Amiram Eldar_ and _M. F. Hasler_, Nov 13 2018

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Last modified April 24 10:11 EDT 2024. Contains 371935 sequences. (Running on oeis4.)