A047683 a(n) = 5^(2*n)*(5^(2*n)-1)*Bernoulli(2*n)/(2*n).

50, -3250, 968750, -635781250, 722480468750, -1257228613281250, 3104408581542968750, -10320446545227050781250, 44440884525382995605468750, -240617847532228950500488281250, 1599915691073966364860534667968750, -12816452064605408400845527648925781250

Offset: 1

Author

N. J. A. Sloane

Keywords

• sign

References

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

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..100
• Index entries for sequences related to Bernoulli numbers.

Crossrefs

Column 4 of A241066.

Row sums of even-indexed rows of A211234.

Programs

PARI

a(n) = 5^(2*n)*(5^(2*n)-1)*bernfrac(2*n)/(2*n) \\ Andrew Howroyd, May 18 2020

Extensions

Offset corrected by Andrew Howroyd, May 18 2020