A143417 - OEIS

%I #6 Jan 28 2014 00:49:33

%S 1,2,3,4,6,8,12,24,5,10,15,16,20,30,40,48,60,80,120,240,7,9,14,18,21,

%T 28,36,42,56,63,72,84,126,168,252,504,32,96,160,480,11,22,33,44,66,88,

%U 132,264,13,26,35,39,45,52,65,70,78,90,91,104,105,112,117,130,140,144,156

%N Irregular triangle in which row n gives the k such that the reduced totient function psi(k) = A002174(n).

%C Row n consists of the divisors of A143407(n) that are not divisors of A143407(r) for r<n. The length of row n is A143408(n).

%H T. D. Noe, <a href="/A143417/b143417.txt">Rows n=1..20, flattened</a>

%e 1,2; 3,4,6,8,12,24; 5,10,15,16,20,30,40,48,60,80,120,240

%Y Cf. A002322 (reduced totient function).

%K nonn,tabf,look

%O 1,2

%A _T. D. Noe_, Aug 13 2008