A129125 Prune the tree structure defined in sequence A129129 yielding a new irregular table with shape sequence A027336.

1, 2, 3, 5, 6, 7, 10, 9, 11, 14, 15, 18, 13, 22, 21, 25, 30, 27, 17, 26, 33, 35, 42, 50, 45, 54, 19, 34, 39, 55, 66, 49, 70, 63, 75, 90, 81

Offset: 0

Author

Alford Arnold, Apr 04 2007

Keywords

• more
• nonn
• tabf

Comments

A000041 begins 1 1 2 3 5 7 11 15 22 30 42 ... and when shifted 0 0 1 1 2 3 5 7 11 15 22 ... by subtraction yielding 1 1 1 2 3 4 6 8 11 15 20 ... shape seq A027336.

Examples

			The original tree begins
   1;
   2;
   3,  4;
   5,  6,  8;
   7, 10,  9, 12, 16;
  11, 14, 15, 20, 18, 24, 32;
  ...
Multiplying by four yields
   4;
   8;
  12, 16;
  20, 24, 32;
  ...
These are the values to be omitted, leaving
   1;
   2;
   3;
   5,  6;
   7, 10,  9;
  11, 14, 15, 18;
  ...
		

Crossrefs

Cf. A000041, A027336, A129129.