A171173 Triangle read by rows in which row n lists A033627(n) together with the first 2n-1 positive integers.

2, 1, 4, 1, 2, 3, 7, 1, 2, 3, 4, 5, 10, 1, 2, 3, 4, 5, 6, 7, 13, 1, 2, 3, 4, 5, 6, 7, 8, 9, 16, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 19, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 22, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 25, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 28, 1

Offset: 1

Author

Omar E. Pol, Feb 23 2010

Keywords

• easy
• nonn
• tabf

Comments

The same as A171172 except the initial term.

Also, a(n) is the length of each component of the n-th L-toothpick added to the structure of A171165.

See also A171175, a permutation of the natural numbers.

Examples

			Triangle begins:
2,1,
4,1,2,3,
7,1,2,3,4,5,
10,1,2,3,4,5,6,7,
13,1,2,3,4,5,6,7,8,9,
16,1,2,3,4,5,6,7,8,9,10,11,
19,1,2,3,4,5,6,7,8,9,10,11,12,13,
22,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,
25,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..10000
• N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
• Index entries for sequences related to toothpick sequences

Crossrefs

Cf. A000027, A033627, A172310, A171164, A161165, A161166, A171172, A171174, A171175, A171176, A171177, A171178.

Programs

Mathematica

Join[{2,1},Flatten[Table[Flatten[{3n+1,Range[2n+1]}],{n,10}]]] (* Harvey P. Dale, Nov 24 2011 *)