

A079318


a(0) = 1; for n > 0, a(n) = (3^(A000120(n)1) + 1)/2.


4



1, 1, 1, 2, 1, 2, 2, 5, 1, 2, 2, 5, 2, 5, 5, 14, 1, 2, 2, 5, 2, 5, 5, 14, 2, 5, 5, 14, 5, 14, 14, 41, 1, 2, 2, 5, 2, 5, 5, 14, 2, 5, 5, 14, 5, 14, 14, 41, 2, 5, 5, 14, 5, 14, 14, 41, 5, 14, 14, 41, 14, 41, 41, 122, 1, 2, 2, 5, 2, 5, 5, 14, 2, 5, 5, 14, 5, 14, 14, 41, 2, 5, 5, 14, 5, 14, 14, 41, 5, 14, 14
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OFFSET

0,4


REFERENCES

Alex Fink, Aviezri S. Fraenkel and Carlos Santos, LIM is not slim, International Journal of Game Theory, May 2013
David Singmaster, On the cellular automaton of Ulam and Warburton, M500 Magazine of the Open University, #195 (December 2003), pp. 27.


LINKS



FORMULA

a(n) = Sum_{i+j+k=n, 0<=k<=j<=i<=n} (n!/(i!*j!*k!) mod 2).  Benoit Cloitre, Jul 02 2004


EXAMPLE

If written as a triangle:
1;
1;
1,2;
1,2,2,5;
1,2,2,5,2,5,5,14;
1,2,2,5,2,5,5,14,2,5,5,14,5,14,14,41;
1,2,2,5,2,5,5,14,2,5,5,14,5,14,14,41,2,5,5,14,5,14,14,41,5,14,14,41,14,41,41,122;
(End)


MATHEMATICA

a[n_] := (3^(DigitCount[n, 2, 1]  1) + 1)/2; a[0] = 1; Array[a, 100, 0] (* Amiram Eldar, Jul 29 2023 *)


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



STATUS

approved



