OFFSET
0,2
COMMENTS
a(a(a(...1))) (n times) gives A006978(n)
LINKS
T. D. Noe, Table of n, a(n) for n = 0..1023
Eric Weisstein's World of Mathematics, Rule 110
Wikipedia, Rule 110
FORMULA
EXAMPLE
For n=19, the evolution after one step is
0, 1, 0, 0, 1, 1 (n=19)
1, 1, 0, 1, 1, 1 (a(n)=55)
So a(n)=55.
MATHEMATICA
a[n_] :=
FromDigits[
Drop[Part[CellularAutomaton[110, {IntegerDigits[n, 2], 0}], 1], -1],
2]; Table[a[n], {n, 0, 100}]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Ben Branman, Jan 30 2011
STATUS
approved