A066904 Triangular numbers in A006577.

1, 3, 6, 15, 15, 10, 10, 21, 21, 21, 6, 105, 105, 28, 28, 28, 28, 28, 15, 15, 15, 15, 15, 15, 36, 36, 36, 36, 10, 10, 10, 21, 21, 21, 21, 21, 21, 21, 78, 21, 91, 91, 55, 55, 55, 45, 45, 45, 45, 45, 45, 45, 45, 45, 120, 120, 120, 120, 120, 120, 120, 120, 66, 66, 136, 136

Offset: 0

Author

K. B. Subramaniam (kb_subramaniambalu(AT)yahoo.com), Dec 20 2001

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..2000

Crossrefs

Cf. A006577.

Programs

Mathematica

Select[Table[Length[NestWhileList[If[EvenQ[#],#/2,3#+1]&,n,#!=1&]]-1, {n,1000}],OddQ[Sqrt[8#+1]]&] (* Harvey P. Dale, Feb 06 2015 *)

Extensions

More terms from Sascha Kurz, Mar 23 2002