A172087 - OEIS

%I #11 Apr 22 2021 12:36:51

%S 1,1,3,3,15,15,21,21,15,15,33,33,1365,1365,3,3,255,255,399,399,165,

%T 165,69,69,1365,1365,3,3,435,435,7161,7161,255,255,3,3,959595,959595,

%U 3,3,6765,6765,903,903,345,345,141,141

%N A001897 with terms repeated.

%t b[n_] := -2*(2^(2*n - 1) - 1)*BernoulliB[2*n]; t = Table[b[n], {n, 0, 30}] // Denominator; A172087 = Transpose[{t, t}] // Flatten (* _Jean-François Alcover_, Jan 11 2016 *)

%Y Cf. A001897, A172087.

%K nonn

%O 0,3

%A _Paul Curtz_, Jan 25 2010

%E More terms from _Jean-François Alcover_, Jan 11 2016

%E Edited by _N. J. A. Sloane_, Apr 22 2021.