login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A166553 Triangle read by rows: expansion of p(x,t) = -exp(x*t)(2*(1 - 2*exp(t)) - 2*exp(t))/(1 + exp(t)), with coefficient of x^n scaled by multiplication by (n!*(n + 2)!/4). 0

%I #13 Mar 12 2014 16:37:04

%S 1,3,3,0,24,12,-30,0,180,60,0,-720,0,1440,360,2520,0,-12600,0,12600,

%T 2520,0,120960,0,-201600,0,120960,20160,-771120,0,3810240,0,-3175200,

%U 0,1270080,181440,0,-61689600,0,101606400

%N Triangle read by rows: expansion of p(x,t) = -exp(x*t)(2*(1 - 2*exp(t)) - 2*exp(t))/(1 + exp(t)), with coefficient of x^n scaled by multiplication by (n!*(n + 2)!/4).

%C I think the rows are indexed by t = 0, 1, 2, ..., and in each row we expand the polynomial in powers of x. - _N. J. A. Sloane_, Dec 14 2010

%C Row sums are 1, 6, 36, 210, 1080, 5040, 60480, 1315440, 5443200, -558835200, 718502400,...

%e {1},

%e {3, 3},

%e {0, 24, 12},

%e {-30, 0, 180, 60},

%e {0, -720, 0, 1440, 360},

%e {2520, 0, -12600, 0, 12600, 2520},

%e {0, 120960, 0, -201600, 0, 120960, 20160},

%e {-771120, 0,3810240, 0, -3175200, 0, 1270080, 181440},

%e {0, -61689600, 0, 101606400, 0, -50803200, 0, 14515200, 1814400},

%t p[t_] = -Exp[x*t](2*(1 - 2*Exp[t]) - 2*Exp[t])/(1 + Exp[t]);

%t a = Table[ CoefficientList[(n!*(n + 2)!/4)*SeriesCoefficient[

%t Series[p[t], {t, 0, 30}], n], x], {n, 0, 10}];

%t Flatten[a]

%K sign,tabl

%O 0,2

%A _Roger L. Bagula_, Dec 12 2010

%E I rewrote the definition. - _N. J. A. Sloane_, Dec 14 2010

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 31 13:42 EDT 2024. Contains 374800 sequences. (Running on oeis4.)