A171177 Triangle read by rows in which row n lists 3n-1 together with the first 2n-1 numbers <> 0 of A038608, in reverse order.

2, -1, 5, -3, 2, -1, 8, -5, 4, -3, 2, -1, 11, -7, 6, -5, 4, -3, 2, -1, 14, -9, 8, -7, 6, -5, 4, -3, 2, -1, 17, -11, 10, -9, 8, -7, 6, -5, 4, -3, 2, -1, 20, -13, 12, -11, 10, -9, 8, -7, 6, -5, 4, -3, 2, -1, 23, -15, 14, -13, 12, -11, 10, -9, 8, -7, 6, -5, 4, -3, 2, -1, 26, -17, 16, -15

Offset: 1

Author

Omar E. Pol, Feb 23 2010

Keywords

• easy
• sign
• tabf

Comments

Absolute values give A171176.

Note that the partial sums of this sequence give A171178, a permutation of the natural numbers.

Examples

			Triangle begins:
2, -1;
5, -3, 2, -1;
8, -5, 4, -3, 2, -1;
11,-7, 6, -5, 4, -3, 2, -1;
14,-9, 8, -7, 6, -5, 4, -3, 2, -1;
17,-11,10,-9, 8, -7, 6, -5, 4, -3, 2, -1;
20,-13,12,-11,10,-9, 8, -7, 6, -5, 4, -3, 2, -1;
23,-15,14,-13,12,-11,10,-9, 8, -7, 6, -5, 4, -3, 2, -1;
26,-17,16,-15,14,-13,12,-11,10,-9, 8, -7, 6, -5, 4, -3, 2, -1;
		

Crossrefs

Cf. A016789, A038608, A172310, A171164, A161165, A161166, A171172, A171173, A171174, A171175, A171176, A171178.