OFFSET
0,1
COMMENTS
The sequence reaches its fixed point at a(141) = <term with 103 decimal digits; binary representation 340 bits long> after which the sequence stays constant, a(142) = a(143) = a(144), etc.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..142
FORMULA
a(0) = 29; for n >= 1, a(n) = A234742(a(n-1)).
PROG
(PARI)
allocatemem((2^29));
A234742(n) = factorback(subst(lift(factor(Mod(1, 2)*Pol(binary(n)))), x, 2)); \\ After M. F. Hasler's Feb 18 2014 code.
iterates_of_A234742(start, filename) = {my(n=start, prev=-1, prevprev=-1, i=0); until((n==prevprev), write(filename, i, " ", n); prevprev = prev; prev = n; n = A234742(n); i++)} \\ Computes b-file up to the second occurrence of the fixed point.
iterates_of_A234742(29, "b260729.txt")
(Scheme, with memoizing macro definec)
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 04 2015
STATUS
approved