Search: id:A014197 Results 1-1 of 1 results found. %I A014197 %S A014197 2,3,0,4,0,4,0,5,0,2,0,6,0,0,0,6,0,4,0,5,0,2,0,10,0,0,0,2,0,2,0, %T A014197 7,0,0,0,8,0,0,0,9,0,4,0,3,0,2,0,11,0,0,0,2,0,2,0,3,0,2,0,9,0,0, %U A014197 0,8,0,2,0,0,0,2,0,17,0,0,0,0,0,2,0,10,0,2,0,6,0,0,0,6,0,0,0,3 %N A014197 Number of numbers m with Euler phi(m) = n. %C A014197 Carmichael conjectured that there are no 1's in this sequence. %C A014197 Number of cyclotomic polynomials of degree n. - T. D. Noe (noe(AT)sspectra.com), Aug 15 2003 %D A014197 R. K. Guy, Unsolved Problems in Number Theory, section B39. %D A014197 J. Roberts, Lure of The Integers, entry 32, page 182. %H A014197 T. D. Noe, Table of n, a(n) for n = 1..10000 %H A014197 K. Ford, [math/9907204] The number of solutions of phi(x)=m %H A014197 Primefan, Totient Answers For The First 1000 Integers %H A014197 Eric Weisstein's World of Mathematics, Totient Function %H A014197 Eric Weisstein's World of Mathematics, Totient Valence Function %F A014197 Dirichlet g.f.: sum(n>=1, a(n)*n^-s)=zeta(s)*prod(1+1/(p-1)^s-1/p^s) - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 12 2003 %F A014197 lim n ->infinity (1/n)*sum(k=1, n, a(k))=zeta(2)*zeta(3)/zeta(6)=1.94359643682075920505707036... - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 12 2003 %p A014197 with(numtheory): A014197 := n-> nops(invphi(i)); %o A014197 (PARI) A014197(n,m=1) = { n==1 && return(1+(m<2)); my(p,q); sumdiv(n, d, if( d>=m && isprime(d+1), sum( i=0,valuation(q=n\d,p=d+1), A014197(q\p^i, p))))} [From M. F. Hasler (MHasler(AT)univ-ag.fr), Oct 05 2009] %Y A014197 Cf. A058277, A002202, A032446. %Y A014197 Cf. A070243 (partial sums). %Y A014197 For records see A131934, A097942. %Y A014197 Sequence in context: A122059 A164917 A166238 this_sequence A021438 A025638 A025639 %Y A014197 Adjacent sequences: A014194 A014195 A014196 this_sequence A014198 A014199 A014200 %K A014197 nonn,nice,easy,new %O A014197 1,1 %A A014197 N. J. A. Sloane (njas(AT)research.att.com). %E A014197 Additional comments from Jud McCranie (j.mccranie(AT)comcast.net), Oct 10 2000 %E A014197 Replaced a geocities.com URL - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 30 2009 Search completed in 0.002 seconds