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

Author

Hugo Pfoertner and Rainer Rosenthal, Feb 14 2021

Keywords

• nonn
• more
• hard

Comments

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

Crossrefs

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

Formula

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

Extensions

a(19) from Hugo Pfoertner, Mar 15 2021