A160465 First left hand column of the Eta triangle A160464

-1, -11, -114, -3963, -104745, -3926745, -198491580, -26045435115, -2153099119815, -219022225836750, -26891482281048000, -3921682257253270125, -670160622793156369875, -132649536458654226136125

Offset

2,2

Links

Table of n, a(n) for n=2..15.

Maple

nmax:=15; c(2) := -1/3: for n from 3 to nmax do c(n) := (2*n-2)*c(n-1)/(2*n-1)-1/ ((n-1)*(2*n-1)) end do: for n from 2 to nmax do GCS(n-1) := ln(1/(2^(-(2*(n-1)-1-floor(ln(n-1)/ ln(2))))))/ln(2); p(n) := 2^(-GCS(n-1))*(2*n-1)!; ETA(n, 1) := p(n)*c(n) end do: seq(ETA(n, 1), n=2..nmax);

Crossrefs

A160464 is the Eta triangle.

The GCS(n) sequence equals the geometric Connell sequence A049039(n).

The p(n) sequence is given by A160473.

Sequence in context: A121196 A251261 A332729 * A125446 A287838 A271477

Adjacent sequences: A160462 A160463 A160464 * A160466 A160467 A160468

Keyword

easy,sign

Author

Johannes W. Meijer, May 24 2009

Status

approved