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!)
A080955 Square array of numbers related to the incomplete gamma function, read by antidiagonals. 6
1, 1, 1, 1, 2, 2, 1, 3, 5, 6, 1, 4, 10, 16, 24, 1, 5, 17, 38, 65, 120, 1, 6, 26, 78, 168, 326, 720, 1, 7, 37, 142, 393, 872, 1957, 5040, 1, 8, 50, 236, 824, 2208, 5296, 13700, 40320, 1, 9, 65, 366, 1569, 5144, 13977, 37200, 109601, 362880, 1, 10, 82, 538, 2760, 10970, 34960, 100026 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Table of n, a(n) for n=0..62.

FORMULA

T(k,n) = n! * Sum{j=0..n} k^j/j!.

E.g.f. of k-th row: exp(k*x)/(1-x).

T(k,n) = A089258(n,k).

EXAMPLE

Array begins:

k=0: 1 1 2 6 24 ...

k=1: 1 2 5 16 65 ...

k=2: 1 3 10 38 168 ...

k=3: 1 4 17 78 393 ...

k=4: 1 5 26 142 824 ...

...

MATHEMATICA

T[0, k_] := k!; T[n_, k_] := k!*Sum[n^j/j!, {j, 0, k}];

Table[T[n-k, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jan 17 2018 *)

CROSSREFS

Rows: A000142, A000522, A010842, A053486, A053487, A080954.

Transposed version: A089258.

Sequence in context: A095788 A071944 A309495 * A125231 A117919 A309106

Adjacent sequences:  A080952 A080953 A080954 * A080956 A080957 A080958

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry, Feb 26 2003

EXTENSIONS

Corrected by Philippe Deléham, Dec 12 2003

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 May 30 09:19 EDT 2020. Contains 334717 sequences. (Running on oeis4.)