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 A130075 #12 Jun 08 2021 07:57:57 %S A130075 6,30,570,10830,4422630,93776970,44871187170,1003806502230, %T A130075 518297165370030,6422911941109705770,150213298561349961630, %U A130075 1966475018690546370358170,1109139879321302763891656370 %N A130075 a(n) = (5^p - 3^p - 2^p)/p, where p = prime(n). %C A130075 p divides 5^p - 3^p - 2^p = A130072(p) for prime p. %C A130075 p^(k+1) divides A130072(p^k) for prime p = {2,3,5,19} = A130076(n) and all k>0. %C A130075 2 divides a(n). 3 divides a(n). 5 divides a(n) for n>1. 19 divides a(n) for n>2. 19^2 divides a(n) for n in A091178(n) or prime(n) in A002476. %F A130075 a(n) = (5^prime(n) - 3^prime(n) - 2^prime(n))/prime(n). %F A130075 a(n) = A130072(prime(n))/prime(n). %t A130075 Table[(5^Prime[n]-3^Prime[n]-2^Prime[n])/Prime[n],{n,1,20}] %t A130075 (5^#-3^#-2^#)/#&/@Prime[Range[20]] (* _Harvey P. Dale_, May 02 2012 *) %Y A130075 Cf. A130072, A130073, A130074, A130076, A091178, A002476. %K A130075 nonn %O A130075 1,1 %A A130075 _Alexander Adamchuk_, May 06 2007