A071021 Square array T(i,j) = Bernoulli(2i)*Bernoulli(2j) read by antidiagonals: denominators.

1, 6, 6, 30, 36, 30, 42, 180, 180, 42, 30, 252, 900, 252, 30, 66, 180, 1260, 1260, 180, 66, 2730, 396, 900, 1764, 900, 396, 2730, 6, 16380, 396, 1260, 1260, 396, 16380, 6, 510, 36, 81900, 2772, 900, 2772, 81900, 36, 510, 798, 3060, 180, 114660, 396, 396, 114660

Offset

0,2

Links

Table of n, a(n) for n=0..51.

Maple

f:=(i, j)->denom(bernoulli(2*i)*bernoulli(2*j)):lon:=5:i:=[seq(op([seq(k, k=0..2*s-1), seq(2*s-2-k, k=0..2*s-2)]), s=1..lon)]:j:=[0, seq(op([seq(k, k=0..2*s), seq(2*s-1-k, k=0..2*s-1)]), s=1..lon)]:seq(f(i[n], j[n]), n=1..min(nops(i), nops(j))); (C. Ronaldo)

Crossrefs

Cf. A071020.

Sequence in context: A055522 A078637 A147799 * A279865 A321528 A074002

Adjacent sequences: A071018 A071019 A071020 * A071022 A071023 A071024

Keyword

nonn,tabl,frac

Author

N. J. A. Sloane, May 24 2002

Status

approved