A189731 -id:A189731 - cp's OEIS frontend

A242926 a(n) = denominator of B(0,n), where B(n,n) = 0, B(n-1,n) = 1/n and otherwise B(m,n) = B(m-1,n+1) - B(m-1,n).

1, 1, 1, 2, 1, 6, 1, 4, 3, 5, 1, 4, 1, 7, 15, 8, 1, 18, 1, 10, 21, 11, 1, 24, 5, 13, 9, 14, 1, 30, 1, 16, 11, 17, 35, 12, 1, 19, 39, 20, 1, 42, 1, 22, 9, 23, 1, 48, 7, 25, 17, 26, 1, 54, 55, 28, 19, 29, 1, 20, 1

Offset: 0

Paul Curtz, May 26 2014

nonn

The numerators are A189731(n).
B(0,n) = 0, 1, 1, 3/2, 2, 17/6, 4, 23/4, 25/3, 61/5, 18, 107/4, 40, 421/7, ...
is a super autosequence as defined in A242563.
The positive integers in B(0,n) give A064723(n). Corresponding rank: A006093(n+1). B(0,n) is linked to the primes A000040.
Divisor of B(0,n), n > 0: 1, 1, 1, 2, 2, 4, 5, ... = A172128(n+1).
Common (LCM) denominators for the antidiagonals: 1, 1, 1, 2, 2, 6, 6, 12, 12, ... = A139550(n+1)?.
1 = 1
1/2 +  3/2 = 2
1/3 +  5/6 + 17/6 = 4
1/4 + 7/12 +  7/4 + 23/4 = 25/3
etc.
The positive terms of the first bisection are the sum of the corresponding antidiagonal terms upon the 0's.
0 followed by A001610(n), i.e., 0, 0, 2, 3, 6, 10, 17, ... is an autosequence of the second kind.

Cf. A000204, A175386, A001610, A189731, A139550, A242563.

Table[Denominator[(LucasL[n+1]-1)/(n+1)], {n, 0, 100}] (* Artur Jasinski, Nov 06 2022 *)

a(2n+1) = A175386(n).
a(n) = denominator(A001610(n)/(n+1)). [edited by Michel Marcus, Nov 14 2022]
a(n) = denominator((A000204(n+1) - 1)/(n+1)). - Artur Jasinski, Nov 06 2022

a(24)-a(60) from Jean-François Alcover, May 26 2014

A242947 a(n) = n / A242926(n-1).

Original entry on oeis.org

1, 2, 3, 2, 5, 1, 7, 2, 3, 2, 11, 3, 13, 2, 1, 2, 17, 1, 19, 2, 1, 2, 23, 1, 5, 2, 3, 2, 29, 1, 31, 2, 3, 2, 1, 3, 37, 2, 1, 2, 41, 1, 43, 2, 5, 2, 47, 1, 7, 2, 3, 2, 53, 1, 1, 2, 3, 2, 59, 3, 61, 2

Offset: 1

Paul Curtz, May 27 2014

nonn

a(n) = n: A008578.
a(2n) = 2, 2, 1, 2, 2, 3, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 3,... .
A242926 is the denominator of a super autosequence based on 1/n. See A189731 and A242563.

			a(1)=1/1, a(2)=2/1=2, a(3)=3/1=3, a(4)=4/2=2, a(5)=5/1=5, a(6)=6/6=1, a(7)=7/1=7, a(8)=8/4=2, ... .

Cf. A242926, A008578, A189731, A242563.

Edited by N. J. A. Sloane, Jun 12 2014

cp's OEIS Frontend

A242926 a(n) = denominator of B(0,n), where B(n,n) = 0, B(n-1,n) = 1/n and otherwise B(m,n) = B(m-1,n+1) - B(m-1,n).

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