A328314 Lexicographically earliest infinite sequence such that a(i) = a(j) => A025586(i) = A025586(j) for all i, j.

1, 2, 3, 4, 3, 3, 5, 6, 5, 3, 5, 3, 7, 5, 8, 3, 5, 5, 9, 10, 11, 5, 8, 12, 9, 7, 13, 5, 9, 8, 13, 14, 15, 5, 8, 5, 16, 9, 17, 7, 13, 11, 18, 5, 19, 8, 13, 20, 21, 9, 22, 5, 8, 13, 13, 23, 18, 9, 17, 8, 24, 13, 13, 11, 18, 15, 17, 25, 26, 8, 13, 27, 13, 16, 28, 9, 22, 17, 29, 30, 31, 13, 13, 32, 33, 18, 34, 9, 17, 19, 13, 8, 35

Offset

1,2

Comments

Restricted growth sequence transform of A025586, the largest value in '3x+1' trajectory of n.

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for sequences related to 3x+1 (or Collatz) problem

Prog

(PARI)
up_to = 65537;
rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om, invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om, invec[i], i); outvec[i] = u; u++ )); outvec; };
A025586(n) = { my(r=n); while(n>2, if(n%2, n=3*n+1; if(n>r, r=n), n/=2)); (r); }; \\ From A025586
v328314 = rgs_transform(vector(up_to, n, A025586(n)));
A328314(n) = v328314[n];

Crossrefs

Cf. A025586.

Cf. also A322973.

Sequence in context: A017839 A242294 A234347 * A286245 A279849 A106826

Adjacent sequences: A328311 A328312 A328313 * A328315 A328316 A328317

Keyword

nonn

Author

Antti Karttunen, Oct 14 2019

Status

approved