cp's OEIS Frontend

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.

A103856 Smallest prime factor of prime(n)! - prime(n)# + 1.

This page as a plain text file.
%I A103856 #17 Dec 30 2024 02:12:07
%S A103856 1,1,7,4831,3673,16349,5240507,4159,83,3911,401,61,66935021479,199,73,
%T A103856 152249,379,5014363,181,191,277,155893,35851,431,1499
%N A103856 Smallest prime factor of prime(n)! - prime(n)# + 1.
%C A103856 a(26) has 160 digits and is too large to be included here.
%H A103856 Amiram Eldar, <a href="/A103856/b103856.txt">Table of n, a(n) for n = 1..26</a>
%H A103856 Reinhard Zumkeller, <a href="/A103855/a103855.txt">p(n)! - p(n)# + 1</a>.
%F A103856 a(n) = A020639(A103855(n)).
%o A103856 (PARI) a(n) = if(n>2, factor(prime(n)!-factorback(primes(n))+1)[1, 1], 1); \\ _Jinyuan Wang_, Dec 30 2024
%Y A103856 Cf. A020639, A103855, A103857, A103891.
%K A103856 nonn
%O A103856 1,3
%A A103856 _Reinhard Zumkeller_, Feb 20 2005