A320488 Inverse Euler transform of A004104.

1, 1, 0, 1, 4, 14, 65, 572, 7434, 163284, 5736792, 342169618, 33534958026, 5442700283638, 1484664947481018, 664513607618098252, 508538464299684269212, 635542752091150346032474, 1374528064543284187245552390, 4842758246111267151697826493193, 29772724415959420224886585241636839

Offset

0,5

Comments

The inverse Euler transform of A004104 does not give the number of connected self-dual signed graphs. The combinatorial interpretation of this sequence is that of either a connected self-dual signed graph or a pair of distinct connected signed graphs which are dual to each other (but not self-dual). - Andrew Howroyd, Jan 26 2020

Links

Andrew Howroyd, Table of n, a(n) for n = 0..50

N. J. A. Sloane, Transforms

Crossrefs

Cf. A004102, A004104, A053465, A320499.

Sequence in context: A119857 A305654 A241465 * A126787 A187742 A347432

Adjacent sequences: A320485 A320486 A320487 * A320489 A320490 A320491

Keyword

nonn

Author

N. J. A. Sloane, Oct 25 2018

Extensions

Definition edited by Andrew Howroyd, Jan 26 2020

Status

approved