File: sage/combinat/expnums.pyx (starting at line 17)
Compute the first $n$ exponential numbers around $aa$, starting
with the zero-th.
INPUT:
n -- C machine int
aa -- C machine int
OUTPUT:
A list of length $n$.
ALGORITHM: We use the same integer addition algorithm as GAP.
This is an extension of Bell's triangle to the general case of
exponential numbers. The recursion performs $O(n^2)$ additions,
but the running time is dominated by the cost of the last integer
addition, because the growth of the integer results of partial
computations is exponential in $n$. The algorithm stores $O(n)$
integers, but each is exponential in $n$.
EXAMPLES:
sage: expnums(10, 1)
[1, 1, 2, 5, 15, 52, 203, 877, 4140, 21147]
sage: expnums(10, -1)
[1, -1, 0, 1, 1, -2, -9, -9, 50, 267]
sage: expnums(1, 1)
[1]
sage: expnums(0, 1)
[]
sage: expnums(-1, 0)
[]
AUTHOR:
-- Nick Alexander
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