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 A124942 #13 Aug 27 2025 11:47:59 %S A124942 675,1323,1372,1480,1750,1875,2295,2920,3100,3856,4095,4120,4180,4275, %T A124942 4375,5175,5427,5643,5775,5980,6370,6375,6520,6723,6820,7150,7155, %U A124942 7203,7240,7245,7960,8325,8883,8920,9075,9207,9555,9620,9625,9747,9855,9940 %N A124942 Numbers k such that k and k+5 are 5-almost primes. %H A124942 Charles R Greathouse IV, <a href="/A124942/b124942.txt">Table of n, a(n) for n = 1..10000</a> %e A124942 675=3^3*5^2, 680=2^3*5*17; 1323=3^3*7^2, 1328=2^4*83. %t A124942 Select[Range[10000],PrimeOmega[#]==PrimeOmega[#+5]==5&] (* _James C. McMahon_, Dec 13 2024 *) %t A124942 Select[Partition[Range[10000],6,1],PrimeOmega[#[[1]]]==PrimeOmega[#[[6]]]==5&][[;;,1]] (* _Harvey P. Dale_, Aug 27 2025 *) %o A124942 (PARI) isok(n) = (bigomega(n) == 5) && (bigomega(n+5) == 5); \\ _Michel Marcus_, Oct 11 2013 %Y A124942 Cf. A124940, A124941. %K A124942 nonn,changed %O A124942 1,1 %A A124942 _Zak Seidov_, Nov 13 2006