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A131818 A130296 + A002260 - A000012. Triangle read by rows: row n consists of n, 2, 3, 4, ..., n. 3
1, 2, 2, 3, 2, 3, 4, 2, 3, 4, 5, 2, 3, 4, 5, 6, 2, 3, 4, 5, 6, 7, 2, 3, 4, 5, 6, 7, 8, 2, 3, 4, 5, 6, 7, 8, 9, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums = A034856; (1, 4, 8, 13, 19, 26, 34, ...).

LINKS

Table of n, a(n) for n=1..78.

FORMULA

A130296 + A002260 - A000012 as infinite lower triangular matrices.

T(n, 1) = n, T(n, k) = k for k > 1. - Michel Marcus, Feb 12 2014

EXAMPLE

First few rows of the triangle:

  1;

  2, 2;

  3, 2, 3;

  4, 2, 3, 4;

  5, 2, 3, 4, 5;

  6, 2, 3, 4, 5, 6;

  7, 2, 3, 4, 5, 6, 7;

  ...

MATHEMATICA

Table[Join[{n}, Range[2, n]], {n, 15}]//Flatten (* Harvey P. Dale, Feb 24 2021 *)

PROG

(PARI) t(n, k) = if (k==1, n, k); \\ Michel Marcus, Feb 12 2014

CROSSREFS

Cf. A130296, A002260, A034856.

Sequence in context: A338283 A104324 A193212 * A222111 A222438 A222027

Adjacent sequences:  A131815 A131816 A131817 * A131819 A131820 A131821

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Jul 18 2007

EXTENSIONS

More terms from Michel Marcus, Feb 12 2014

STATUS

approved

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Last modified May 18 01:52 EDT 2022. Contains 353779 sequences. (Running on oeis4.)