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”).

A292977
Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. exp(-k*x)/(1 - x).
3
1, 1, 1, 1, 0, 2, 1, -1, 1, 6, 1, -2, 2, 2, 24, 1, -3, 5, -2, 9, 120, 1, -4, 10, -12, 8, 44, 720, 1, -5, 17, -34, 33, 8, 265, 5040, 1, -6, 26, -74, 120, -78, 112, 1854, 40320, 1, -7, 37, -138, 329, -424, 261, 656, 14833, 362880, 1, -8, 50, -232, 744, -1480, 1552, -360, 5504, 133496, 3628800
OFFSET
0,6
COMMENTS
A(n,k) is the k-th inverse binomial transform of A000142 evaluated at n.
Can be considered as extension of the array A089258 to columns with negative indices via A089258(n,k) = A(n,-k) or, vice versa, A(n,k) = A089258(n,-k). - Max Alekseyev, Mar 06 2018
LINKS
FORMULA
T(n, k) = n! * Sum_{j=0..n} (-k)^j/j!. - Max Alekseyev, Mar 06 2018
E.g.f. of column k: exp(-k*x)/(1 - x).
EXAMPLE
Square array begins:
n=0: 1, 1, 1, 1, 1, 1, ...
n=1: 1, 0, -1, -2, -3, -4, ...
n=2: 2, 1, 2, 5, 10, 17, ...
n=3: 6, 2, -2, -12, -34, -74, ...
n=4: 24, 9, 8, 33, 120, 329, ...
n=5: 120, 44, 8, -78, -424, -1480, ...
...
E.g.f. of column k: A_k(x) = 1 + (1 - k)*x/1! + (k^2 - 2*k + 2)*x^2/2! + (-k^3 + 3*k^2 - 6*k + 6) x^3/3! + (k^4 - 4*k^3 + 12*k^2 - 24*k + 24)*x^4/4! + ...
MATHEMATICA
Table[Function[k, n! SeriesCoefficient[Exp[-k x]/(1 - x), {x, 0, n}]][j - n], {j, 0, 10}, {n, 0, j}] // Flatten
FullSimplify[Table[Function[k, Exp[-k] Gamma[n + 1, -k]][j - n], {j, 0, 10}, {n, 0, j}]] // Flatten
CROSSREFS
Columns: A000142 (k=0), A000166 (k=1), A000023 (k=2), A010843 (k=3, with offset 0).
Main diagonal: A134095 (absolute values).
Sequence in context: A156186 A156233 A251725 * A295381 A351420 A331283
KEYWORD
sign,tabl
AUTHOR
Ilya Gutkovskiy, Sep 27 2017
STATUS
approved