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 A136354 #9 Aug 14 2025 00:56:36
%S A136354 9,15,105,3465,15015,765765,33948915,334639305,3234846615,
%T A136354 100280245065,3710369067405,1369126185872445,32706903329175075,
%U A136354 307444891294245705,211829530101735290745,961380175077106319535,762374478836145311391255
%N A136354 a(n) is the smallest odd composite number m such that m+2 is prime and the set of distinct prime factors of m consists of the first n odd primes.
%C A136354 This sequence is different from A070826 and A118750.
%e A136354 a(1)=9 because k=1 with prime factor 3 and 9+2=11, prime
%t A136354 a[n_]:=(c=Product[Prime[k],{k,2,n+1}]; For[m=1,!(!PrimeQ[c(2m-1)]&&PrimeQ[c(2m-1)+2]&&Length[FactorInteger[c(2m-1)]]==n),m++ ]; c(2m-1)); Table[a[n],{n,17}] (* _Farideh Firoozbakht_, Aug 12 2009 *)
%Y A136354 Cf. A136349-A136353, A136355-A136358, A070826, A118750.
%K A136354 easy,nonn
%O A136354 1,1
%A A136354 _Enoch Haga_, Dec 25 2007
%E A136354 Edited, corrected and extended by _Farideh Firoozbakht_, Aug 12 2009