This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A300959 #8 Mar 18 2018 09:50:24 %S A300959 3,3,3,3,3,3,3,4,3,4,3,3,3,4,4,3,4,3,3,3,4,3,3,4,3,3,3,4,3,4,3,3,4,4, %T A300959 4,3,3,4,3,4,4,3,4,3,5,4,3,3,3,3,4,3,3,4,3,4,4,3,3,3,5,4,4,3,3,4,3,4, %U A300959 3,3,4,4,4,3,3,4,4,3,4,4,4,4,3,5,3,4,3 %N A300959 Number of prime factors of the n-th Lucas-Carmichael number. %C A300959 The number of prime factors is always >= 3. %H A300959 Tim Johannes Ohrtmann, <a href="/A300959/b300959.txt">Table of n, a(n) for n = 1..10000</a> %F A300959 a(n) = A001221(A006972(n)). %o A300959 (PARI) islc(n)=my(f=factor(n)); for(i=1, #f[, 1], if((n+1)%(f[i, 1]+1) || f[i, 2]>1, return(0))); #f[, 1]>1; \\ from A006972 %o A300959 lista(nn) = for (n=1, nn, if (islc(n), print1(omega(n), ", "))); \\ _Michel Marcus_, Mar 17 2018 %Y A300959 Cf. A006972 (Lucas-Carmichael numbers). %Y A300959 Cf. A216925, A216926, A216927, A217002, A217003, A217091 (Lucas-Carmichael numbers with 3 to 8 prime factors). %Y A300959 Cf. A216928 (Least Lucas-Carmichael number with n prime factors). %K A300959 nonn %O A300959 1,1 %A A300959 _Tim Johannes Ohrtmann_, Mar 17 2018