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A132118 Triangle read by rows: T(n,k) = n*(n-1)/2 + 2*k - 1. 2
1, 2, 4, 4, 6, 8, 7, 9, 11, 13, 11, 13, 15, 17, 19, 16, 18, 20, 22, 24, 26, 22, 24, 26, 28, 30, 32, 34, 29, 31, 33, 35, 37, 39, 41, 43, 37, 39, 41, 43, 45, 47, 49, 51, 53, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..1275 (rows 1..50)
EXAMPLE
First few rows of the triangle are:
1;
2, 4;
4, 6, 8;
7, 9, 11, 13;
11, 13, 15, 17, 19;
16, 18, 20, 22, 24, 26;
22, 24, 26, 28, 30, 32, 34;
29, 31, 33, 35, 37, 39, 41, 43;
...
MATHEMATICA
Table[(n(n-1))/2+2k-1, {n, 20}, {k, n}]//Flatten (* Harvey P. Dale, Mar 26 2022 *)
CROSSREFS
Column 1 is A000124(n-1).
Main diagonal is A034856.
Row sums are A002411.
Sequence in context: A288574 A135692 A089003 * A221952 A007843 A239826
KEYWORD
nonn,easy,tabl
AUTHOR
Gary W. Adamson, Aug 10 2007
EXTENSIONS
a(16), a(17) corrected by Georg Fischer, Jul 01 2020
Name changed and terms a(56) and beyond from Andrew Howroyd, Apr 17 2021
STATUS
approved

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Last modified March 28 14:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)