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A144693 Triangle read by rows, A000012 * (3*A144328 - 2*A000012), where A000012 means a lower triangular matrix of all 1's. 2
1, 2, 1, 3, 2, 4, 4, 3, 8, 7, 5, 4, 12, 14, 10, 6, 5, 16, 21, 20, 13, 7, 6, 20, 28, 30, 26, 16, 8, 7, 24, 35, 40, 39, 32, 19, 9, 8, 28, 42, 50, 52, 48, 38, 22, 10, 9, 32, 49, 60, 65, 64, 57, 44, 25, 11, 10, 36, 56, 70, 78, 80, 76, 66, 50, 28 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
Sum_{k=1..n} T(n, k) = A064808(n).
T(n, k) = (3*k -5 +3*[k=1])*(n-k+1). - G. C. Greubel, Oct 19 2021
EXAMPLE
Partial sums by columns of the triangle (3*A144328 - 2*A000012):
1;
1, 1;
1, 1, 4;
1, 1, 4, 7;
1, 1, 4, 7, 10;
...
First few rows of the triangle:
1;
2, 1
3, 2, 4;
4, 3, 8, 7;
5, 4, 12, 14, 10;
6, 5, 16, 21, 20, 13;
7, 6, 20, 28, 30, 26, 16;
8, 7, 24, 35, 40, 39, 32, 19;
...
MATHEMATICA
T[n_, k_]:= (3*k -5 +3*Boole[k==1])*(n-k+1);
Table[T[n, k], {n, 12}, {k, n}]//Flatten (* G. C. Greubel, Oct 19 2021 *)
PROG
(Magma)
A144693:= func< n, k | k eq 1 select n else (3*k-5)*(n-k+1) >;
[A144693(n, k): k in [1..n], n in [1..12]]; // G. C. Greubel, Oct 19 2021
(Sage)
def A144693(n, k): return (3*k -5 +3*bool(k==1))*(n-k+1)
flatten([[A144693(n, k) for k in (1..n)] for n in (1..12)]) # G. C. Greubel, Oct 19 2021
CROSSREFS
Sequence in context: A034390 A368671 A183912 * A328399 A328171 A029139
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Sep 19 2008
STATUS
approved

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Last modified June 23 15:01 EDT 2024. Contains 373651 sequences. (Running on oeis4.)