

A320488


Inverse Euler transform of A004104.


1



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

0,5


COMMENTS

The inverse Euler transform of A004104 does not give the number of connected selfdual signed graphs. The combinatorial interpretation of this sequence is that of either a connected selfdual signed graph or a pair of distinct connected signed graphs which are dual to each other (but not selfdual).  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 A129219
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



