A334546 - OEIS

%I #8 May 06 2020 01:49:28

%S 1,1,1,1,1,0,1,1,1,0,1,1,2,0,0,1,1,3,2,0,0,1,1,4,4,2,0,0,1,1,5,9,12,2,

%T 0,0,1,1,6,14,37,22,2,0,0,1,1,7,23,93,146,68,2,0,0,1,1,8,32,203,602,

%U 772,166,2,0,0,1,1,9,46,399,2126,5847,4449,534,2,0,0

%N Array read by antidiagonals: T(n,k) is the number of unlabeled connected loopless multigraphs with n nodes of degree k or less.

%C This sequence may be derived from A333893 by inverse Euler transform.

%H Andrew Howroyd, <a href="/A334546/b334546.txt">Table of n, a(n) for n = 0..377</a> (antidiagonals 0..26)

%F Column k is the inverse Euler transform of column k of A333893.

%e Array begins:

%e ==============================================

%e n\k | 0 1 2   3    4     5      6       7

%e ----+-----------------------------------------

%e   0 | 1 1 1   1    1     1      1       1 ...

%e   1 | 1 1 1   1    1     1      1       1 ...

%e   2 | 0 1 2   3    4     5      6       7 ...

%e   3 | 0 0 2   4    9    14     23      32 ...

%e   4 | 0 0 2  12   37    93    203     399 ...

%e   5 | 0 0 2  22  146   602   2126    6308 ...

%e   6 | 0 0 2  68  772  5847  34126  164965 ...

%e   7 | 0 0 2 166 4449 66289 716141 6021463 ...

%e   ...

%Y Columns k=3..5 are A243391, A289157, A334547.

%Y Main diagonal is A334546.

%Y Cf. A289987, A328682 (regular), A333893 (not necessarily connected).

%K nonn,tabl

%O 0,13

%A _Andrew Howroyd_, May 05 2020