A127773 - OEIS

A127773

Triangle read by rows: row n consists of n-1 zeros followed by n(n+1)/2.

1, 0, 3, 0, 0, 6, 0, 0, 0, 10, 0, 0, 0, 0, 15, 0, 0, 0, 0, 0, 21, 0, 0, 0, 0, 0, 0, 28, 0, 0, 0, 0, 0, 0, 0, 36, 0, 0, 0, 0, 0, 0, 0, 0, 45, 0, 0, 0, 0, 0, 0, 0, 0, 0, 55

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,3

LINKS

Table of n, a(n) for n=1..55.

EXAMPLE

First few rows of the triangle are:

0, 3;

0, 0, 6;

0, 0, 0, 10;

0, 0, 0, 0, 15;

...

MATHEMATICA

Flatten[Table[{(n(n+1))/2, Table[0, {n}]}, {n, 10}]] (* Harvey P. Dale, Apr 03 2011 *)

CROSSREFS

Cf. A127648, A000217, A127774.

Sequence in context: A273089 A362021 A330735 * A194498 A193986 A376203

Adjacent sequences: A127770 A127771 A127772 * A127774 A127775 A127776

KEYWORD

nonn,easy,tabl

AUTHOR

Gary W. Adamson, Jan 28 2007

STATUS

approved