OFFSET
0,2
COMMENTS
For connection to A002872, A002874, and other columns of A162663, see the formula in A162663. - Andrey Zabolotskiy, Oct 25 2017
REFERENCES
T. S. Motzkin, Sorting numbers for cylinders and other classification numbers, in Combinatorics, Proc. Symp. Pure Math. 19, AMS, 1971, pp. 167-176.
LINKS
T. S. Motzkin, Sorting numbers for cylinders and other classification numbers, in Combinatorics, Proc. Symp. Pure Math. 19, AMS, 1971, pp. 167-176. [Annotated, scanned copy]
FORMULA
E.g.f.: exp(exp(x*y)+y*(exp(x)-1)-1).
EXAMPLE
Triangle begins:
1;
. 2;
. 1, 5;
. 1, 6, 15;
. 1, 11, 30, 52;
. 1, 20, 80, 150, 203;
. 1, 37, 210, 525, 780, 877;
...
MAPLE
egf:= exp(exp(x*y)+y*(exp(x)-1)-1):
T:= (n, k)-> n!*coeff(series(coeff(series(egf, y, k+1)
, y, k), x, n+1), x, n):
seq(seq(T(n, k), k=min(n, 1)..n), n=0..10); # Alois P. Heinz, Mar 28 2013
PROG
(PARI) T(n, k) = { my(y = 'y + 'y*O('y^k), x = 'x + 'x*O('x^n); ); n!*polcoeff(polcoeff(exp(exp(x*y)+y*(exp(x)-1)-1), n, 'x), k, 'y); }
for(n=0, 10, for(k=0, n, print1(T(n, k), ", ")); print()); /* print triangle */
\\ Michel Marcus, Mar 27 2013
(PARI) listpols(n)= {my(z = t + t*O(t^n)); zp = exp(exp(z)-1+(exp(p*z)-1)/p); for (i=0, n, print(i!*polcoeff(zp, i, t)); ); } \\ Michel Marcus, Mar 27 2013
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
EXTENSIONS
Edited by Vladeta Jovovic, Sep 17 2003
Name corrected by Andrey Zabolotskiy, Oct 22 2017
STATUS
approved