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A324693
Number of simple graphs on n unlabeled nodes with minimum degree exactly 1.
4
0, 1, 1, 4, 12, 60, 378, 3843, 64455, 1921532, 104098702, 10348794144, 1893781768084, 639954768875644, 400905675004630820, 467554784370658979194, 1019317687720204607541914, 4170177760438554428852944352, 32130458453030025927403299167172
OFFSET
1,4
FORMULA
a(n) = A002494(n) - A261919(n).
First differences of A141580. - Andrew Howroyd, Jan 11 2021
CROSSREFS
Column k = 1 of A294217.
A diagonal of A263293.
The labeled version is A327227.
The generalization to set-systems is A327335, with covering case A327230.
Unlabeled covering graphs are A002494.
Sequence in context: A357711 A374656 A337291 * A276707 A350561 A083484
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Sep 03 2019
STATUS
approved