A340921 a(n) is the number of distinct resistances that can be produced using at most n unit resistors in a planar network.

1, 2, 4, 8, 16, 36, 80, 194, 506, 1400, 4024, 11870, 35200, 104836, 311686, 929088, 2776618, 8321128, 24967712, 74985708

Offset

0,2

Comments

The relation of this sequence to A340920 is the analog of the relation of A180414 to A337517.

Links

Table of n, a(n) for n=0..19.

Formula

a(n) = A180414(n) for n <= 9, a(n) < A180414(n) for n >= 10.

Crossrefs

Cf. A153588, A174284, A174286, A180414, A337517, A340920.

Sequence in context: A034341 A341536 A034342 * A180414 A007669 A034343

Adjacent sequences: A340918 A340919 A340920 * A340922 A340923 A340924

Keyword

nonn,more,hard

Author

Hugo Pfoertner and Rainer Rosenthal, Feb 14 2021

Extensions

a(19) from Hugo Pfoertner, Mar 15 2021

Status

approved