A170950 Inverse permutation to A170949.

1, 3, 2, 4, 7, 6, 8, 5, 9, 13, 12, 14, 11, 15, 10, 16, 21, 20, 22, 19, 23, 18, 24, 17, 25, 31, 30, 32, 29, 33, 28, 34, 27, 35, 26, 36, 43, 42, 44, 41, 45, 40, 46, 39, 47, 38, 48, 37, 49, 57, 56, 58, 55, 59, 54, 60, 53, 61, 52, 62, 51, 63, 50, 64, 73, 72, 74, 71, 75, 70, 76, 69, 77, 68, 78

Offset: 1

Author

N. J. A. Sloane, Feb 21 2010

Keywords

• nonn
• tabf

Comments

a(A002522(n-1)) = A002061(n); a(A002061(n)) = A174114(n). - Reinhard Zumkeller, Mar 08 2010

Row sums are n^3+(n+1)^3 [A005898](1,9,35,91,189,...). - Vincenzo Librandi, Feb 22 2010

The even central polygonal numbers divided by 2 give the central column of the triangle. - Omar E. Pol, Aug 16 2011

Examples

			                           1
                        3  2  4
                     7  6  8  5  9
                 13 12 14 11 15 10 16
              21 20 22 19 23 18 24 17 25
           31 30 32 29 33 28 34 27 35 26 36
        43 42 44 41 45 40 46 39 47 38 48 37 49
     57 56 58 55 59 54 60 53 61 52 62 51 63 50 64
  73 72 74 71 75 70 76 69 77 68 78 67 79 66 80 65 81
		

References

• J. H. Conway, Personal communication, Feb 19 2010

Links

• R. Zumkeller, Table of n, a(n) for n = 1..10000
• Index entries for sequences that are permutations of the natural numbers [From _Reinhard Zumkeller_, Mar 08 2010]