login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A260196
1, -3, followed by -1's.
2
1, -3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
OFFSET
0,2
COMMENTS
1/(n+1) is the inverse Akiyama-Tanigawa transform of A164555(n)/A027642(n).
For more on the Akiyama-Tanigawa transform, see Links (correction: page 7 read here A164555 instead of A027641) and A177427.
Here:
1, -3, -1, -1, -1, -1, ...
4, -4, 0, 0, 0, 0, ...
8, -8, 0, 0, 0, 0, ...
16, -16, 0, 0, 0, 0, ...
etc.
Other process, using signed A130534(n), different of A008275(n):
1, 1/1, 1,
1, 4, ( 1, -1)/1, -3,
1, 4, 8, ( 2, -3, 1)/2, -1,
1, 4, 8, 16, * ( 6, -11, 6, -1)/6, = -1,
1, 4, 8, 16, 32, ( 24, -50, 35, -10, 1)/24, -1,
1, 4, 8, 16, 32, 64, (120, -274, 225, -85, 15, -1)/120, -1,
etc. etc. etc.
Via the modified Stirling numbers of the first kind, the second triangle, Iw(n), is the inverse of Worpitzky transform A163626(n).
a(n) is the third sequence of a family beginning with
1, 1, 1, 1, 1, 1, 1, 1, ... = A000012(n)
1, 0, 0, 0, 0, 0, 0, 0, 0, ... = A000007(n)
1, -3, -1, -1, -1, -1, -1, -1, -1, -1, ... .
A000012(n) is the inverse Akiyama-Tanigawa transform of A000007(n), with or without its second term.
A000007(n) is the inverse Akiyama-Tanigawa transform of A000012(n), with or without its second term.
a(n) is the inverse Akiyama-Tanigawa transform of 2^n omitting the second term i.e. 2.
LINKS
Masanobu Kaneko, The Akiyama-Tanigawa algorithm for Bernoulli numbers, Journal of Integer Sequences, 3(2000), article 00.2.9
FORMULA
Inverse Akiyama-Tanigawa transform of A151821(n).
From Colin Barker, Sep 11 2015: (Start)
a(n) = -1 for n>1.
a(n) = a(n-1) for n>2.
G.f.: -(2*x^2-4*x+1) / (x-1).
(End)
PROG
(PARI) first(m)=vector(m, i, i--; if(i>1, -1, if(i==0, 1, if(i==1, -3)))) \\ Anders Hellström, Aug 28 2015
(PARI) Vec(-(2*x^2-4*x+1)/(x-1) + O(x^100)) \\ Colin Barker, Sep 11 2015
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Jul 19 2015
STATUS
approved