login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A255009 Array T(n,k) read by ascending antidiagonals, where T(n,k) is the denominator of polygamma(n, 1) - polygamma(n, k). 1
1, 1, 1, 1, 1, 2, 1, 1, 4, 6, 1, 1, 4, 36, 12, 1, 1, 8, 108, 144, 60, 1, 1, 4, 216, 864, 3600, 20, 1, 1, 8, 324, 3456, 108000, 3600, 140, 1, 1, 8, 1944, 10368, 2160000, 12000, 176400, 280, 1, 1, 16, 1944, 124416, 32400000, 2160000, 4116000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

COMMENTS

See A255008.

LINKS

Table of n, a(n) for n=0..52.

MATHEMATICA

T[n_, k_] := (-1)^(n+1)*n!*HarmonicNumber[k-1, n+1] // Denominator; Table[T[n-k, k], {n, 0, 10}, {k, 1, n}] // Flatten

CROSSREFS

Cf. A001008, A002805, A007406, A007407, A255006, A255007, A255008 (numerators).

Sequence in context: A090668 A307977 A295259 * A156579 A322266 A190284

Adjacent sequences:  A255006 A255007 A255008 * A255010 A255011 A255012

KEYWORD

nonn,frac,easy

AUTHOR

Jean-Fran├žois Alcover, Feb 12 2015

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 19 22:36 EST 2020. Contains 332061 sequences. (Running on oeis4.)