%I A020725
%S A020725 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,
%T A020725 28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,
               51,
%U A020725 52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,
               75
%N A020725 Integers >= 2.
%C A020725 This sequence is closed under multiplication by any integer k > 0. The 
               primitive elements of the sequence (those not divisible by any smaller 
               element) are the primes, A000040. - Frank Adams-Watters (FrankTAW(AT)Netscape.net), 
               May 22 2006
%H A020725 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/
               RecursiveSequences.html">Recursive Sequences</a>
%H A020725 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               PierceExpansion.html">Pierce Expansion</a>
%F A020725 G.f. (2x-x^2)/(1-x)^2. E.g.f. (x+1)e^x-1. Dirichlet g.f. zeta(s) + zeta(s-1). 
               a(n) = n + 1 (for n>0). - Frank Adams-Watters (FrankTAW(AT)Netscape.net), 
               May 22 2006
%Y A020725 Sequence in context: A001489 A023443 A099570 this_sequence A119972 A131738 
               A000027
%Y A020725 Adjacent sequences: A020722 A020723 A020724 this_sequence A020726 A020727 
               A020728
%K A020725 nonn
%O A020725 1,1
%A A020725 N. J. A. Sloane (njas(AT)research.att.com).