A134403 Triangle read by rows: row n consists of (n, n, (n+1), (n+2), (n+3), ...).

0, 1, 1, 2, 2, 3, 3, 3, 4, 5, 4, 4, 5, 6, 7, 5, 5, 6, 7, 8, 9, 6, 6, 7, 8, 9, 10, 11, 7, 7, 8, 9, 10, 11, 12, 13, 8, 8, 9, 10, 11, 12, 13, 14, 15, 9, 9, 10, 11, 12, 13, 14, 15, 16, 17, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 11, 11, 12, 13, 14, 15, 16

Offset

0,4

Comments

Row sums = A005449: (0, 2, 7, 15, 26, 40, 57, ...).

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Formula

Equals (A000012 * A134402 + A134402 * A000012) - A000012.

Example

First few rows of the triangle:
  0;
  1, 1;
  2, 2, 3;
  3, 3, 4, 5;
  4, 4, 5, 6,  7;
  5, 5, 6, 7,  8,  9;
  6, 6, 7, 8,  9, 10, 11;
  7, 7, 8, 9, 10, 11, 12, 13;
  ...

Mathematica

Table[{n, n+Range[0, n-1]}, {n, 0, 20}]//Flatten (* Harvey P. Dale, Dec 26 2020 *)

Crossrefs

Cf. A134402, A005449.

Sequence in context: A165103 A281579 A194311 * A124882 A262518 A085578

Adjacent sequences: A134400 A134401 A134402 * A134404 A134405 A134406

Keyword

nonn,tabl

Author

Gary W. Adamson, Oct 23 2007

Extensions

Leading term changed from 1 to 0 by N. J. A. Sloane, Apr 06 2008

Corrected and extended by Harvey P. Dale, Dec 26 2020

Status

approved