A047683 - OEIS

%I #18 Mar 28 2024 23:54:56

%S 50,-3250,968750,-635781250,722480468750,-1257228613281250,

%T 3104408581542968750,-10320446545227050781250,

%U 44440884525382995605468750,-240617847532228950500488281250,1599915691073966364860534667968750,-12816452064605408400845527648925781250

%N a(n) = 5^(2*n)*(5^(2*n)-1)*Bernoulli(2*n)/(2*n).

%D J. W. Milnor and J. D. Stasheff, Characteristic Classes, Princeton, 1974, p. 283.

%H Andrew Howroyd, <a href="/A047683/b047683.txt">Table of n, a(n) for n = 1..100</a>

%H <a href="/index/Be#Bernoulli">Index entries for sequences related to Bernoulli numbers</a>.

%o (PARI) a(n) = 5^(2*n)*(5^(2*n)-1)*bernfrac(2*n)/(2*n) \\ _Andrew Howroyd_, May 18 2020

%Y Column 4 of A241066.

%Y Row sums of even-indexed rows of A211234.

%K sign

%O 1,1

%A _N. J. A. Sloane_

%E Offset corrected by _Andrew Howroyd_, May 18 2020