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 A227608 Denominators of A225825(n) difference table written by antidiagonals. 2

%I

%S 1,2,2,6,3,6,2,3,3,2,30,15,15,15,30,2,15,15,15,15,2,42,21,105,105,105,

%T 21,42,2,21,21,105,105,21,21,2,30,15,105,105,105,105,105,15,30,2,15,

%U 15,105,105,105,105,15,15,2,66,33,165,165,1155,231,1155,165,165,33,66,2,33,33,165,165,231,231,165,165,33,33,2

%N Denominators of A225825(n) difference table written by antidiagonals.

%e 1,

%e -1/2, 1/2,

%e -1/6, -2/3, -1/6,

%e 1/2, 1/3, -1/3, -1/2,

%e 7/30, 11/15, 16/15, 11/15, 7/30,

%e -3/2, -19/15, -8/15, 8/15, 19/15, 3/2,

%e -31/42, -47/21, -368/105, -424/105, -368/105, -47/21, -31/42.

%e Row sums: 1, 0/2, -6/6, 0/6, 90/30, 0/30, -3570/210, 0/210, 32550/210,... .

%e Are the denominators A034386(n+1)?

%e Reduced row sums: 1, 0, -1, 0, 3, 0, -17, 0, 155,... = -A036968(n+1)? See A226158(n+2). First 100 terms checked by Jean-François Alcover.

%t max = 12; b[0] = 1; b[n_] := Numerator[ BernoulliB[n, 1/2] - (n+1)*EulerE[n, 0]]; t = Table[b[n], {n, 0, max}] / Table[ Sum[ Boole[ PrimeQ[d+1]]/(d+1), {d, Divisors[n]}] // Denominator, {n, 0, max}]; dt = Table[ Differences[t, n], {n, 0, max}]; Table[ dt[[n-k+1, k]] // Denominator, {n, 1, max}, {k, 1, n}] // Flatten (* _Jean-François Alcover_, Aug 12 2013 *)

%Y Cf. A085738

%K nonn,frac,tabl

%O 0,2

%A _Paul Curtz_, Aug 10 2013

%E More terms from _Jean-François Alcover_, Aug 12 2013

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Last modified October 22 08:00 EDT 2019. Contains 328315 sequences. (Running on oeis4.)