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 A360840 #15 Feb 16 2025 08:34:04 %S A360840 432,2592,139968,444528,472392,995328,3456000,5174928,6561000, %T A360840 10125000,15552000,15804072,17496000,25299648,28449792,37340352, %U A360840 54675000,63700992,85957848,88723728,99574272,120891312,144027072,169869312,177147000,197413632,253125000,259308000 %N A360840 3-full numbers (A036966) sandwiched between twin primes. %H A360840 Amiram Eldar, <a href="/A360840/b360840.txt">Table of n, a(n) for n = 1..10000</a> %H A360840 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TwinPrimes.html">Twin Primes</a>. %H A360840 Wikipedia, <a href="https://en.wikipedia.org/wiki/Powerful_number#Generalization">Powerful number: Generalization</a>. %H A360840 <a href="/index/Pow#powerful">Index entries for sequences related to powerful numbers</a>. %e A360840 432 = 2^4 * 3^3 is a term since it is 3-full and 431 and 433 are twin primes. %t A360840 Select[6*Range[10^6], PrimeQ[# - 1] && PrimeQ[# + 1] && Min[FactorInteger[#][[;; , 2]]] > 2 &] %o A360840 (PARI) is(n) = isprime(n-1) && isprime(n+1) && vecmin(factor(n)[,2]) > 2; %Y A360840 Intersection of A014574 and A036966. %Y A360840 Subsequence of A113839. %K A360840 nonn %O A360840 1,1 %A A360840 _Amiram Eldar_, Feb 23 2023