A092676 Numerators of coefficients in the series for inverf(2x/sqrt(Pi)).
1, 1, 7, 127, 4369, 34807, 20036983, 2280356863, 49020204823, 65967241200001, 15773461423793767, 655889589032992201, 94020690191035873697, 655782249799531714375489, 44737200694996264619809969
Offset: 1
Examples
Inverf(2x/sqrt(Pi)) = x + x^3/3 + 7x^5/30 + 127x^7/630 + 4369x^9/22680 + 34807x^11/178200 + ... The first few coefficients are 1, 1, 7/6, 127/90, 4369/2520, 34807/16200, 20036983/7484400, 2280356863/681080400, ...
Links
- G. C. Greubel, Table of n, a(n) for n = 1..230
- G. Alkauskas, Algebraic and abelian solutions to the projective translation equation, arXiv preprint arXiv:1506.08028 [math.AG], 2015-2016; Aequationes Math. 90 (4) (2016), 727-763.
- J. M. Blair, C. A. Edwards and J. H. Johnson, Rational Chebyshev approximations for the inverse of the error function, Math. Comp. 30 (1976), 827-830.
- L. Carlitz, The inverse of the error function, Pacific J. Math., 13 (1963), 459-470.
- Eric Weisstein, Mathematica program and first 50 terms of the series
- Eric Weisstein's World of Mathematics, Inverse Erf
- Wikipedia, Error Function
Programs
-
Maple
c:=proc(n) option remember; if n <= 0 then 1 else add( c(k)*c(n-k-1)/((k+1)*(2*k+1)), k=0..n-1 ) fi; end;
-
Mathematica
Numerator[CoefficientList[Series[InverseErf[2*x/Sqrt[Pi]], {x, 0, 50}], x]][[2 ;; ;; 2]] (* G. C. Greubel, Jan 09 2017 *)
Extensions
Edited by N. J. A. Sloane, Nov 15 2007
Comments