A336938 The maximum values of the sets A(n), where A(0) = {0} and A(n+1) is the union of A(n) and the Collatz orbit of the smallest natural number missing in A(n).

0, 4, 16, 16, 52, 52, 52, 160, 160, 160, 160, 160, 160, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232, 9232

Offset

0,2

Links

Table of n, a(n) for n=0..46.

Prog

(PARI) firstMiss(A) = { my(i); if(#A == 0 || A[1] > 0, return(0)); for(i = 1, A[#A] + 1, if(!setsearch(A, i), return(i))); };
iter(A) = { my(a = firstMiss(A)); while(!setsearch(A, a), A = setunion(A, Set([a])); a = if(a % 2, 3*a+1, a/2)); A; };
makeVec(m) = { my(v = [], A = Set([0]), i); for(i = 1, m, v = concat(v, A[#A]); if (i < m, A = iter(A))); v; };
makeVec(47)

Crossrefs

Cf. A061641, A336256.

Sequence in context: A224113 A223876 A223801 * A232516 A220109 A207283

Adjacent sequences: A336935 A336936 A336937 * A336939 A336940 A336941

Keyword

nonn

Author

Markus Sigg, Aug 08 2020

Status

approved