A187044 Row sums of number triangle A070895.
1, 2, 4, 9, 22, 59, 170, 525, 1716, 5917, 21362, 80533, 315516, 1281913, 5383622, 23330405, 104084736, 477371217, 2246811730, 10839493637, 53528916508, 270318789249, 1394426035918, 7341439399397, 39413238225512, 215607783811041
Offset: 0
Links
- G. C. Greubel, Table of n, a(n) for n = 0..795
Programs
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Mathematica
CoefficientList[Series[E^(x+x^2/2)*(Sqrt[Pi/2]*Erf[x/Sqrt[2]]+1), {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Aug 15 2013 *)
Formula
E.g.f.: exp(x+x^2/2)*(sqrt(pi/2)*ERF(x/sqrt(2)) + 1).
Conjecture: a(n) -2*a(n-1) +(2-n)*a(n-2) +(n-2)*a(n-3)=0. - R. J. Mathar, Sep 29 2012
a(n) ~ (sqrt(2)+sqrt(Pi))/2 * exp(sqrt(n)-n/2-1/4)*n^(n/2) * (1+7/(24*sqrt(n))). - Vaclav Kotesovec, Aug 15 2013
a(n) = A193361(n+2). - Vaclav Kotesovec, Feb 14 2014