A260729 Iterates of A234742, starting from value a(0) = 29, with a(1) = A234742(a(0)), a(2) = A234742(a(1)), etc.

29, 33, 93, 217, 341, 961, 2821, 7409, 8973, 53625, 94325, 225169, 470517, 1349089, 4076589, 22862205, 40165377, 506257425, 918577233, 1042701969, 5347778553, 76822655445, 242180261569, 243151045949, 835744242025, 1398202164821, 7718585207745, 17886399120625, 36628781776125, 140199249091321, 579641775855025, 3110633457224293, 9887055813390673

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)
(definec (A260729 n) (if (zero? n) 29 (A234742 (A260729 (- n 1)))))

Crossrefs

Cf. A234742, A260712, A260713.

Cf. also A244323, A260735, A260441 for iterations starting from other values.

Sequence in context: A294737 A261521 A114180 * A295153 A031172 A159022

Adjacent sequences: A260726 A260727 A260728 * A260730 A260731 A260732

Keyword

nonn

Author

Antti Karttunen, Aug 04 2015

Status

approved