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 A137525 A triangular sequence of coefficients based on an expansion of a Catenoid like Sheffer expansion function: g(t) = t; f(t) = -1/t; p(x,t) = Exp[x*(t)]*(1 - f(t)^2). 0
 2, 0, -1, 0, 6, 0, -1, 0, 0, 24, 0, -2, 0, 0, 0, 120, 0, -6, 0, 0, 0, 0, 720, 0, -24, 0, 0, 0, 0, 0, 5040, 0, -120, 0, 0, 0, 0, 0, 0, 40320, 0, -720, 0, 0, 0, 0, 0, 0, 0, 362880, 0, -5040, 0, 0, 0, 0, 0, 0, 0, 0, 3628800, 0, -40320, 0, 0, 0, 0, 0, 0, 0, 0, 0, 39916800, 0, -362880, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 479001600, 0, -3628800 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row sums: {1, 5, 22, 114, 696, 4920, 39600, 357840, 3588480, 39553920, 475372800}; Since this sequence seems to start at the quadratic level, there may be lower extensions to it. When I started doing Sheffer sequences I noticed the similarity between the {f,g} data of Weierstrass definitions of minimal surfaces and the two function Sheffer sequence generators. Here is the relationship that seems to hold: Weierstrass{f,g)-> Sheffer{g,fbar} LINKS Table of n, a(n) for n=1..88. FORMULA g(t) = t; f(t) = -1/t; p(x,t) = Exp[x*(t)]*(1 - f(t)^2)=Sum(P(x,n)*t^n/n!,{n,0,Infinity}]; out_n,m=n!*(n+2)!*Coefficients(P(x,n)). EXAMPLE {2, 0, -1}, {0, 6, 0, -1}, {0, 0, 24, 0, -2}, {0, 0, 0, 120, 0, -6}, {0, 0, 0, 0, 720, 0, -24}, {0, 0, 0, 0, 0, 5040, 0, -120}, {0, 0, 0, 0, 0, 0, 40320, 0, -720}, {0, 0, 0, 0, 0, 0, 0, 362880, 0, -5040}, {0, 0, 0, 0, 0, 0, 0, 0, 3628800, 0, -40320}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 39916800, 0, -362880}, {0, 0, 0, 0,0, 0, 0, 0, 0, 0, 479001600, 0, -3628800} MATHEMATICA Clear[p, f, g] g[t_] = t; f[t] = -1/t; p[t_] = Exp[x*g[t]]*(1 - f[t]^2); g = Table[ FullSimplify[ExpandAll[(n!)*(n + 2)!*SeriesCoefficient[Series[p[t], {t, 0, 30}], n]]], {n, 0, 10}]; a = Table[ CoefficientList[n!*(n + 2)!*SeriesCoefficient[ FullSimplify[Series[p[t], {t, 0, 30}]], n], x], {n, 0, 10}]; Flatten[a] CROSSREFS Sequence in context: A078924 A229141 A137526 * A166335 A109187 A265089 Adjacent sequences: A137522 A137523 A137524 * A137526 A137527 A137528 KEYWORD uned,tabf,sign AUTHOR Roger L. Bagula, Apr 24 2008 STATUS approved

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Last modified July 15 12:56 EDT 2024. Contains 374332 sequences. (Running on oeis4.)