Irregular triangle E(n,g) counting not necessarily connected 4-regular simple graphs on n vertices with girth exactly g.
A185140
Irregular triangle E(n,g) counting not necessarily connected 4-regular simple graphs on n vertices with girth exactly g.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =1a(5) =16a(6) =0a(7) =58a(8) =2a(9) =264a(10) =2a(11) =1535a(12) =12a(13) =10755a(14) =31a(15) =87973a(16) =220a(17) =803973a(18) =1606a(19) =8020967a(20) =16829a(21) =86029760a(22) =193900a(23) =983431053a(24) =2452820a(25) =11913921910a(26) =32670331a(27) =1a(28) =152352965278a(29) =456028487
External references
- oeis: A185140