login
A306960
Trajectory of 1 under repeated application of x -> A306958(x).
3
1, 10, 11, 20, 91, 3628810, 3780821, 4234421, 16030, 151932, 3659870, 6230161, 303231, 2261, 151390, 3659781, 6230170, 756822, 2600820, 1965783, 6230170, 756822, 2600820, 1965783, 6230170, 756822, 2600820, 1965783, 6230170, 756822, 2600820
OFFSET
1,2
COMMENTS
The trajectory converges to the cycle of length 4 given in A306959.
REFERENCES
P. Kiss, A generalization of a problem in number theory, Math. Sem. Notes Kobe Univ., 5 (1977), no. 3, 313-317. MR 0472667 (57 #12362).
LINKS
P. Kiss, A generalization of a problem in number theory, [Hungarian], Mat. Lapok, 25 (No. 1-2, 1974), 145-149.
H. J. J. te Riele, Iteration of number-theoretic functions, Nieuw Archief v. Wiskunde, (4) 1 (1983), 345-360. See Example I.1.d.
MAPLE
a:= proc(n) option remember; `if`(n=1, 1, add(
d!*binomial(10, d), d=convert(a(n-1), base, 10)))
end:
seq(a(n), n=1..30); # Alois P. Heinz, Nov 28 2023
MATHEMATICA
a[n_]:=Total[Binomial[10, #]*#!&/@IntegerDigits[n]]; NestWhileList[a, 1, UnsameQ, All] (* Ray Chandler, Nov 30 2023 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
N. J. A. Sloane, Mar 18 2019
EXTENSIONS
a(1)=1 inserted by Georg Fischer, Nov 28 2023
STATUS
approved