A333730 Number of simple 4-regular bipartite graphs with 2n nodes.

0, 0, 0, 1, 1, 4, 14, 130, 1981, 62616, 2806508, 158937367, 10773254138, 855658147832, 78558952717569, 8251166899386729, 982806390786806618, 131756175056777580011, 19748565975966429686408, 3289970442222058710279611, 605948437043760750748781907, 122796504004669690100342096563

Offset

1,6

Links

Table of n, a(n) for n=1..22.

Formula

Euler transform of A006824.

Crossrefs

Column k=4 of A008327.

Sequence in context: A137056 A302021 A006824 * A344201 A254718 A162077

Adjacent sequences: A333727 A333728 A333729 * A333731 A333732 A333733

Keyword

nonn

Author

Andrew Howroyd, Apr 03 2020

Status

approved