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A246661 Run Length Transform of swinging factorials (A056040). 9
1, 1, 1, 2, 1, 1, 2, 6, 1, 1, 1, 2, 2, 2, 6, 6, 1, 1, 1, 2, 1, 1, 2, 6, 2, 2, 2, 4, 6, 6, 6, 30, 1, 1, 1, 2, 1, 1, 2, 6, 1, 1, 1, 2, 2, 2, 6, 6, 2, 2, 2, 4, 2, 2, 4, 12, 6, 6, 6, 12, 6, 6, 30, 20, 1, 1, 1, 2, 1, 1, 2, 6, 1, 1, 1, 2, 2, 2, 6, 6, 1, 1, 1, 2, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
COMMENTS
For the definition of the Run Length Transform see A246595.
LINKS
FORMULA
a(2^n-1) = n$ where n$ is the swinging factorial of n, A056040(n).
MATHEMATICA
f[n_] := n!/Quotient[n, 2]!^2; Table[Times @@ (f[Length[#]]&) /@ Select[ Split[ IntegerDigits[n, 2]], #[[1]] == 1&], {n, 0, 85}] (* Jean-François Alcover, Jul 11 2017 *)
PROG
(Sage) # uses[RLT from A246660]
A246661_list = lambda len: RLT(lambda n: factorial(n)/factorial(n//2)^2, len)
A246661_list(88)
(Python)
# use RLT function from A278159
from math import factorial
def A246661(n): return RLT(n, lambda m: factorial(m)//factorial(m//2)**2) # Chai Wah Wu, Feb 04 2022
CROSSREFS
Sequence in context: A025242 A356696 A163982 * A246660 A346422 A245405
KEYWORD
nonn,base
AUTHOR
Peter Luschny, Sep 07 2014
STATUS
approved

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Last modified March 28 16:12 EDT 2024. Contains 371254 sequences. (Running on oeis4.)