A075652 Triangle read by rows in which the n-th row is an arithmetic progression of n terms with a common difference of n, and the first term is chosen the lowest possible so that no number appears twice.

1, 2, 4, 3, 6, 9, 7, 11, 15, 19, 8, 13, 18, 23, 28, 14, 20, 26, 32, 38, 44, 22, 29, 36, 43, 50, 57, 64, 31, 39, 47, 55, 63, 71, 79, 87, 40, 49, 58, 67, 76, 85, 94, 103, 112, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 82, 93, 104, 115, 126, 137, 148, 159, 170, 181, 192, 83

Offset

1,2

Links

Ivan Neretin, Table of n, a(n) for n = 1..5050

Example

Triangle starts:
   1;
   2,  4;
   3,  6,  9;
   7, 11, 15, 19;
   8, 13, 18, 23, 28;
  14, 20, 26, 32, 38, 44;
  22, 29, 36, 43, 50, 57, 64;
  ...

Mathematica

a = {1}; Do[d = Range[0, n - 1]*n; a = Join[a, Min[Complement[Range[Max@a + 1], Flatten@Outer[Plus, a, -d]]] + d], {n, 2, 12}]; a (* Ivan Neretin, Nov 09 2016 *)

Crossrefs

Cf. A075648, A075649, A075650, A075651.

Sequence in context: A371236 A246366 A271865 * A331018 A054428 A095167

Adjacent sequences: A075649 A075650 A075651 * A075653 A075654 A075655

Keyword

nonn,tabl

Author

Amarnath Murthy, Oct 01 2002

Extensions

More terms from David Wasserman, Jan 22 2005

Status

approved