A336994 Entries of A336938 without duplicates.

0, 4, 16, 52, 160, 9232, 13120, 39364, 41524, 250504, 1276936, 6810136, 8153620, 27114424, 50143264, 106358020, 121012864, 593279152, 1570824736, 2482111348, 2798323360, 17202377752, 24648077896, 52483285312, 56991483520, 90239155648, 139646736808

Offset

1,2

Comments

Is this (apart from the first 2 entries) the same as A006885? - R. J. Mathar, Aug 16 2020

Yes, a(n) = A006885(n) for n >= 3. - A.H.M. Smeets, Nov 13 2025

Links

A.H.M. Smeets, Table of n, a(n) for n = 1..97

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, if (length(v) == 0 || v[length(v)] != A[#A], v = concat(v, A[#A])); if (i < m, A = iter(A))); v; };
makeVec(10000)

Crossrefs

Cf. A336938.

Sequence in context: A197132 A266943 A100774 * A107767 A319775 A375307

Adjacent sequences: A336991 A336992 A336993 * A336995 A336996 A336997

Keyword

nonn

Author

Markus Sigg, Aug 10 2020

Extensions

a(16)-a(22) from Jinyuan Wang, Aug 13 2020

a(23)-a(27) from A006885 - A.H.M. Smeets, Nov 15 2025

Status

approved