A144422 a(n) = n!*A144416(n).
1, 3, 62, 5052, 1087104, 487424520, 393702654960, 519740602925040, 1046019551260199040, 3046052768591313895680, 12322848899623787148556800, 67036205966744406283600262400, 477463744343745629221074425625600, 4354451197836949908463868034925593600
Offset: 0
Keywords
Links
- David Applegate and N. J. A. Sloane, Table of n, a(n) for n = 0..100
- Samuele Giraudo and Yannic Vargas, Operads of packed words, quotients, and monomial bases, Proc. 37th Conf. Formal Power Series Alg. Comb., Sém. Lotharingien Combin. (2025) Vol. 93B Art. No. 82. See p. 9.
Crossrefs
Cf. A144416.
Programs
-
Mathematica
t[n_, n_] = 1; t[n_ /; n >= 0, k_] /; 0 <= k <= 3*n := t[n, k] = t[n - 1, k - 1] + (k - 1)*t[n - 1, k - 2] + (1/2)*(k - 1)*(k - 2)*t[n - 1, k - 3]; t[, ] = 0; a[n_] := Sum[t[n, k], {k, 0, 3*n}]; Table[n!*a[n], {n, 0, 20}] (* Michael De Vlieger, Aug 04 2025, after Jean-François Alcover at A144416 *)
Comments