A338587 - OEIS

%I #5 Nov 06 2020 08:38:11

%S 1,2,3,3,4,5,5,4,5,6,7,6,5,7,8,7,7,8,7,11,9,10,11,10,13,9,11,10,11,13,

%T 12,9,11,13,13,11,9,12,13,11,14,10,11,15,9,14,16,17,7,8,19,11,12,13,

%U 14,15,18

%N Numerators of resistance values < 1 ohm that can be obtained from a network of exactly 7 one-ohm resistors, but not from any network with fewer than 7 one-ohm resistors. Denominators are in A338597.

%e The list of the 114 = A338197(7) resistance values, sorted by increasing size of R = a(n)/A338597(n) = A338607(n)/A338600(7), is the union of [1/7, 2/11, 3/14, ..., 14/15, 15/16, 18/19] and of the corresponding reciprocal resistances > 1 ohm [19/18, 16/15, 15/14, ..., 14/3, 11/2, 7].

%Y Cf. A338197, A338597, A338607.

%Y Cf. A338595, A338596, A338598, A338599, A338590 (similar for n = 5..10).

%K nonn,frac,fini,full

%O 1,2

%A _Hugo Pfoertner_, Nov 05 2020