login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A288867 Numerators of the z-sequence for the Sheffer matrix S2*P = A048993*A007318 = A049020. 1
1, 0, -1, 3, -53, 65, -1873, 469, -11191, 55391, -1031191, 1334179, -2126212148, 5653970452, -675022695, 438925403269, -67882510220729, 74577815126027, -91314328938731167, 101372762616408631 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
COMMENTS
The denominators are in A288868.
For a- and z-sequences for Sheffer matrices (infinite lower triangular) see a W. Lang link under A006232, also for references. The a-sequence for Sheffer (exp(exp(x)-1), exp(x) - 1), given in A049020 is a = A006232/A006233.
The combined recurrence for A049020 from these a- and z-sequences is: T(n, 0) = n*Sum_{j=0..n-1} z(j)*T(n-1, j), n >= 1, T(0, 0) = 1; T(n, k) = 0 if k < n, T(n, k) = (n/k)*Sum_{j=0..n-k} a(n)*T(n-1, k-1+j), n >= k >= 1.
LINKS
FORMULA
E.g.f. of r(n) = a(n)/A288868(n), n >= 0: (exp(x)-1)/(log(1+x)*exp(x)).
a(n) = numerator(r(n)) (r(n) in lowest terms).
EXAMPLE
Recurrence for A049020 from a- and z-sequences:
T(1, 0) = 1*1*1 =1; T(1, 1) = (1/1)*1*1*1 = 1, T(2, 0) = 2*(1*1 + 0*1) = 2, T(2, 1) = (2/1)*(1*1*1 + 1*(1/2)*1) = 3, T(2, 2) = (2/2)*1**1 = 1; ...
The rationals r(n) begin: 1, 0, -1/3, 3/4, -53/30, 65/12, -1873/84, 469/4, -11191/15, 55391/10, -1031191/22, 1334179/3, -2126212148/455, ...
CROSSREFS
Sequence in context: A143387 A228452 A269458 * A082484 A187805 A178608
KEYWORD
sign,frac,easy
AUTHOR
Wolfdieter Lang, Jun 20 2017
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 2 10:43 EST 2024. Contains 370466 sequences. (Running on oeis4.)