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.

A067024 Smallest prime p such that p+2 has exactly n distinct prime factors.

This page as a plain text file.
%I A067024 #27 Nov 30 2023 23:16:54
%S A067024 2,13,103,1153,15013,255253,4849843,111546433,4360010653,100280245063,
%T A067024 5245694198743,152125131763603,7149881192889433,421842990380476663,
%U A067024 16294579238595022363,1106494163767990292293,74135108972455349583763,4632891063696575353839163,278970415063349480483707693,24012274383139350058948392193
%N A067024 Smallest prime p such that p+2 has exactly n distinct prime factors.
%H A067024 Sean A. Irvine, <a href="/A067024/b067024.txt">Table of n, a(n) for n = 1..58</a> (terms 1..38 from Michael S. Branicky)
%H A067024 Michael S. Branicky, <a href="/A067024/a067024.py.txt">Python program</a>
%H A067024 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a067/A067024.java">Java program</a> (github)
%F A067024 a(n) = Min_{p in A000040 ; A001221(p+2) = n}.
%e A067024 For n = 1,...,7 the factors of 2+a(n) are as follows: 2*2, 3*5, 3*5*7, 3*5*7*11, 3*5*7*11*13, 3*5*7*11*13*17, 3*5*7*11*13*17*19; i.e., a(n) = A002110(n+1)/2 which is prime for n = 2,...,7.
%o A067024 (Python) # see linked program
%Y A067024 Cf. A000040, A001221, A002110, A053705, A067023.
%K A067024 nonn
%O A067024 1,1
%A A067024 _Labos Elemer_, Dec 29 2001
%E A067024 a(8)-a(15) from _Donovan Johnson_, Jan 21 2009
%E A067024 a(16) and beyond from _Michael S. Branicky_, Feb 07 2023