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A049340
Triangle read by rows: T(n,k) is the number of planar graphs with n >= 1 nodes and 0 <= k <= binomial(n,2) edges, all degrees even.
2
1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 3, 2, 2, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 3, 4, 4, 6, 5, 5, 3, 2, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 3, 4, 7, 9, 15, 17, 22, 14, 16, 5, 4, 0, 1, 0, 0, 0
OFFSET
1,32
LINKS
Sean A. Irvine, Java program (github)
EXAMPLE
Triangle begins:
1;
1, 0;
1, 0, 0, 1;
1, 0, 0, 1, 1, 0, 0;
1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0;
1, 0, 0, 1, 1, 1, 3, 2, 2, 1, 1, 0, 1, 0, 0, 0;
...
CROSSREFS
Rows sums give A049339.
Sequence in context: A131961 A276426 A317872 * A336929 A325524 A010269
KEYWORD
nonn,tabf,easy,nice
AUTHOR
EXTENSIONS
Entry revised by Sean A. Irvine, Jul 29 2021
STATUS
approved