login
A188066
Triangle read by rows: Bell polynomial of the second kind B(n,k) with argument vector (7, 42, 210, 840, 2520, 5040, 5040).
2
7, 42, 49, 210, 882, 343, 840, 11172, 12348, 2401, 2520, 117600, 288120, 144060, 16807, 5040, 1076040, 5433120, 5330220, 1512630, 117649, 5040, 8643600, 89029080, 155296680, 81177810, 14823774, 823543, 0, 60540480, 1306912320, 3884433840, 3360055440, 1087076760, 138355224, 5764801
OFFSET
1,1
COMMENTS
From the explicit write-up of the Bell polynomials we have B(n,k)(7*x^6, 42*x^5, 210*x^4, 840*x^3, 2520*x^2, 5040*x, 5040) = B(n,k)(7, 42, ..., 5040)*x^(7*k-n) for a more general set of arguments.
LINKS
M. Abbas and S. Bouroubi, On new identities for Bell's polynomials, Disc. Math. 293 (1-3) (2005), 5-10.
Vladimir Kruchinin, Derivation of Bell Polynomials of the Second Kind, arXiv:1104.5065 [math.CO], 2011.
John Riordan, Derivatives of composite functions, Bull. Am. Math. Soc. 52 (1946), 664-667.
Eric Weisstein's World of Mathematics, Bell Polynomial.
FORMULA
B(n,k) = (n!/k!)*Sum_{j=0..k} binomial(k,j)*binomial(7*j,n)*(-1)^(k-j).
EXAMPLE
Triangle begins
7;
42, 49;
210, 882, 343;
840, 11172, 12348, 2401;
2520, 117600, 288120, 144060, 16807;
5040, 1076040, 5433120, 5330220, 1512630, 117649;
...
MAPLE
A188066 := proc(n, k) n!/k!*add( binomial(k, j)*binomial(7*j, n)*(-1)^(k-j), j=0..k) ; end proc:
seq(seq(A188066(n, k), k=1..n), n=1..5) ; # R. J. Mathar, Apr 08 2011
# The function BellMatrix is defined in A264428.
# Adds (1, 0, 0, 0, ..) as column 0.
BellMatrix(n -> `if`(n<7, [7, 42, 210, 840, 2520, 5040, 5040][n+1], 0), 9); # Peter Luschny, Jan 29 2016
MATHEMATICA
b[n_, k_] := n!/k!*Sum[ Binomial[k, j]*Binomial[7*j, n]*(-1)^(k - j), {j, 0, k}]; Table[b[n, k], {n, 1, 10}, {k, 1, n}] // Flatten (* Jean-François Alcover, Feb 21 2013, translated from Maxima *)
BellMatrix[f_, len_] := With[{t = Array[f, len, 0]}, Table[BellY[n, k, t], {n, 0, len - 1}, {k, 0, len - 1}]];
rows = 12;
B = BellMatrix[Function[n, If[n<7, {7, 42, 210, 840, 2520, 5040, 5040}[[n + 1]], 0]], rows];
Table[B[[n, k]], {n, 2, rows}, {k, 2, n}] // Flatten (* Jean-François Alcover, Jun 28 2018, after Peter Luschny *)
PROG
(Maxima)
B(n, k):=n!/k!*x^(7*k-n)*sum(binomial(k, j)*binomial(7*j, n)*(-1)^(k-j), j, 0, k);
CROSSREFS
Cf. A188062, A068424 (row 7).
Sequence in context: A176090 A183064 A290045 * A225327 A102532 A297405
KEYWORD
nonn,tabl
AUTHOR
Vladimir Kruchinin, Mar 24 2011
STATUS
approved