Search: id:A032446 Results 1-1 of 1 results found. %I A032446 %S A032446 3,4,4,5,2,6,0,6,4,5,2,10,0,2,2,7,0,8,0,9,4,3,2,11,0,2,2,3,2,9, %T A032446 0,8,2,0,2,17,0,0,2,10,2,6,0,6,0,3,0,17,0,4,2,3,2,9,2,6,0,3,0,17, %U A032446 0,0,2,9,2,7,0,2,2,3,0,21,0,2,2,0,0,7,0,12,4,3,2,12,0,2,0,8,2,10 %N A032446 Number of solutions to phi(k)=2n. %D A032446 Albert H. Beiler, "Recreations in the Theory of Numbers, The Queen of Mathematics Entertains, " Second Edition, Dover Publications, Inc., NY, 1966, page 90. %D A032446 Carl Pomerance, Popular values of Euler's function.Mathematica 27 (1980), 84-89. %H A032446 T. D. Noe, Table of n, a(n) for n=1..5000 %e A032446 If n=8 then phi(x)=2*8=16 is satisfied for only a(8)=6 values of x, viz. 17, 32, 34, 40, 48, 60. %p A032446 with(numtheory); [ seq(nops(invphi(2*n)), n=1..90) ]; %t A032446 t = Table[0, {100} ]; Do[a = EulerPhi[n]; If[a < 202, t[[a/2]]++ ], {n, 3, 10^5} ]; t %Y A032446 Bisection of A014197. %Y A032446 Cf. A000010 and A005277. %Y A032446 Cf. A085758. %Y A032446 Sequence in context: A058559 A112180 A158012 this_sequence A028949 A107574 A053405 %Y A032446 Adjacent sequences: A032443 A032444 A032445 this_sequence A032447 A032448 A032449 %K A032446 nonn,easy,nice %O A032446 1,1 %A A032446 Ursula Gagelmann (gagelmann(AT)altavista.net) %E A032446 Extended by Robin Trew (trew(AT)hcs.harvard.edu). Search completed in 0.001 seconds