login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A047683
a(n) = 5^(2*n)*(5^(2*n)-1)*Bernoulli(2*n)/(2*n).
3
50, -3250, 968750, -635781250, 722480468750, -1257228613281250, 3104408581542968750, -10320446545227050781250, 44440884525382995605468750, -240617847532228950500488281250, 1599915691073966364860534667968750, -12816452064605408400845527648925781250
OFFSET
1,1
REFERENCES
J. W. Milnor and J. D. Stasheff, Characteristic Classes, Princeton, 1974, p. 283.
PROG
(PARI) a(n) = 5^(2*n)*(5^(2*n)-1)*bernfrac(2*n)/(2*n) \\ Andrew Howroyd, May 18 2020
CROSSREFS
Column 4 of A241066.
Row sums of even-indexed rows of A211234.
Sequence in context: A239653 A223661 A224111 * A010564 A183689 A248205
KEYWORD
sign
EXTENSIONS
Offset corrected by Andrew Howroyd, May 18 2020
STATUS
approved