A082009 a(n) is the label of parent node of node n in tree shown in A082007.

0, 0, 1, 3, 3, 1, 6, 6, 2, 9, 9, 2, 12, 12, 4, 15, 15, 16, 18, 18, 16, 21, 21, 17, 24, 24, 17, 27, 27, 4, 30, 30, 31, 33, 33, 31, 36, 36, 32, 39, 39, 32, 42, 42, 5, 45, 45, 46, 48, 48, 46, 51, 51, 47, 54, 54, 47, 57, 57, 5, 60, 60, 61, 63

Offset: 1

Author

N. J. A. Sloane, Oct 06 2009, based on a posting by Steve Witham (sw(AT)tiac.net) to the Math Fun Mailing List, Sep 30 2009

Keywords

• nonn
• easy

Links

• Ivan Neretin, Table of n, a(n) for n = 1..10000

Programs

Mathematica

w = {{0}}; a = ConstantArray[0, 254]; Do[k = 2^Floor@Log2[n - 1]; AppendTo[w, Flatten@Table[w[[n - k]] + (2^k - 1) i, {i, 2^k}]]; a[[w[[-1]]]] = Riffle[#, #] &@w[[-2]], {n, 2, 8}]; a (* Ivan Neretin, Mar 12 2017 *)