OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..253 (first 22 antidiagonals).
Eric Weisstein's World of Mathematics, Grid Graph.
Wikipedia, Acyclic orientation.
FORMULA
T(m,n) = T(n,m).
EXAMPLE
Array begins:
=====================================================
m\n| 1 2 3 4 5 ...
---+-------------------------------------------------
1 | 1 2 4 8 16 ...
2 | 2 14 98 686 4802 ...
3 | 4 98 2398 58670 1435414 ...
4 | 8 686 58670 5015972 428816558 ...
5 | 16 4802 1435414 428816558 128091434266 ...
6 | 32 33614 35118638 36659327366 38261306901842 ...
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Andrew Howroyd, Mar 07 2023
STATUS
approved