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 A345744 #15 Jun 26 2021 15:39:20 %S A345744 728,944,1215,1376,1539,1700,2024,2079,2295,2511,2624,2672,3087,3104, %T A345744 3159,3320,3375,3807,3824,3968,4095,4374,4940,5103,5264,5480,5535, %U A345744 5624,5750,5775,5967,5984,6075,6344,6399,6560,6831,6875,6975,6992,7208,7424,7695,7749,7856 %N A345744 Numbers k such that k and k+1 are products of at least 5 primes. %C A345744 Integers k such that k and k+1 are in A046304. - _Michel Marcus_, Jun 26 2021 %e A345744 728 = 2^3*7*13 is a product of 5 primes, while 729 = 3^6 is a product of 6 primes. Thus, 728 is in this sequence. %p A345744 q:= n-> andmap(x-> numtheory[bigomega](x)>4, [n, n+1]): %p A345744 select(q, [$1..8000])[]; # _Alois P. Heinz_, Jun 26 2021 %t A345744 Select[Range[10000], Total[Transpose[FactorInteger[#]][[2]]] > 4 && Total[Transpose[FactorInteger[# + 1]][[2]]] > 4 &] %o A345744 (Python) %o A345744 from sympy import factorint %o A345744 def ok(n): return all(sum(factorint(n+k).values()) > 4 for k in [0, 1]) %o A345744 print(list(filter(ok, range(8000)))) # _Michael S. Branicky_, Jun 25 2021 %o A345744 (PARI) isok(k) = (bigomega(k) >= 5) && (bigomega(k+1) >= 5); \\ _Michel Marcus_, Jun 26 2021 %Y A345744 Cf. A001222, A046304. %K A345744 nonn %O A345744 1,1 %A A345744 _Tanya Khovanova_, Jun 25 2021