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%I #41 Jul 15 2023 14:02:28
%S 7314,8294,8645,11570,13629,13845,15105,15554,16554,17390,17654,18290,
%T 19005,20405,20769,21489,22010,22154,23001,23114,23529,24530,24765,
%U 24870,24969,25346,26690,26894,26961,27434,27965,28105,29145,29210,29414,29469,29666,30414
%N Numbers k such that k and k+1 are the product of exactly four distinct primes.
%C This sequence is different from A140078. For example, A140078(4) = 9009 = 3^2 * 7 * 11 * 13 is not a term.
%H Seiichi Manyama, <a href="/A318896/b318896.txt">Table of n, a(n) for n = 1..10000</a>
%e n | a(n) | a(n)+1
%e --+-------------------------+-------------------------
%e 1 | 7314 = 2 * 3 * 23 * 53 | 7315 = 5 * 7 * 11 * 19
%e 2 | 8294 = 2 * 11 * 13 * 29 | 8295 = 3 * 5 * 7 * 79
%e 3 | 8645 = 5 * 7 * 13 * 19 | 8646 = 2 * 3 * 11 * 131
%o (PARI) is(n) = omega(n)==4 && omega(n+1)==4 && bigomega(n)==4 && bigomega(n+1)==4 \\ _Felix Fröhlich_, Sep 05 2018
%o (PARI) is(n) = factor(n)[, 2]~ == [1, 1, 1, 1] && factor(n+1)[, 2]~ == [1, 1, 1, 1] \\ _David A. Corneth_, Sep 06 2018
%Y Subsequence of A140078.
%Y Cf. A046386, A052215, A215217, A263990, A318964.
%K nonn
%O 1,1
%A _Seiichi Manyama_, Sep 05 2018
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