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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A137981 Triangle read by rows: expansion of p(x,t) = b(x,t)*u(x,t)*h(x,t) where b(x,t) = t*exp(x*t)/(exp(t)-1), u(x,t) = 1/(1-2*x*t+t^2), and h(x,t) = exp(2*x*t-t^2). 0
 2, -3, 30, -92, -120, 696, 720, -8340, -5220, 24120, 40296, 103680, -722160, -289440, 1216080, -756000, 10579800, 13003200, -73306800, -21281400, 86350320, -71284800, -268531200, 2283140160, 1799884800, -9170280000, -2072407680, 8319024000, 2438553600, -41653241280 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This kind of thinking is what is called a physical "model" of a system. LINKS Table of n, a(n) for n=1..30. FORMULA b(x,t)=t*Exp(x*t)/(Exp(t)-1) u(x,t)=1/(1-2*x*t+t^2) h(x,t)=Exp(2*x*t-t^2) p(x,t)=b(x,t)*u(x,t)*h(x,t)=sum(P(x,n)*t^n/n!,{n,0,Infinity}); out_n,m=(n + 2)!*n!*Coefficients(P(x,n)). EXAMPLE {2}, {-3, 30}, {-92, -120, 696}, {720, -8340, -5220, 24120}, {40296, 103680, -722160, -289440, 1216080}, {-756000, 10579800, 13003200, -73306800, -21281400, 86350320}, {-71284800, -268531200, 2283140160, 1799884800, -9170280000, -2072407680, 8319024000}, MATHEMATICA p[t_] = FullSimplify[(t*Exp[x*t]/(Exp[t] - 1))*(Exp[2*x*t - t^2])/(1 - 2*x*t + t^2)]; Table[ ExpandAll[(n + 2)!*n!*SeriesCoefficient[ Series[p[t], {t, 0, 30}], n]], {n, 0, 10}]; a = Table[ CoefficientList[(n + 2)!*n!*SeriesCoefficient[ Series[p[t], {t, 0, 30}], n], x], {n, 0, 10}]; Flatten[a] CROSSREFS Sequence in context: A296248 A325506 A203431 * A110351 A326224 A270483 Adjacent sequences: A137978 A137979 A137980 * A137982 A137983 A137984 KEYWORD tabl,uned,sign AUTHOR Roger L. Bagula, May 01 2008 STATUS approved

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.

Last modified April 22 05:00 EDT 2024. Contains 371887 sequences. (Running on oeis4.)