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A028317
Even elements in the 5-Pascal triangle A028313.
7
6, 6, 12, 8, 8, 38, 10, 36, 36, 10, 46, 130, 46, 12, 12, 204, 378, 462, 378, 204, 14, 82, 582, 840, 840, 582, 82, 14, 96, 1422, 1680, 1422, 96, 16, 1210, 3102, 3102, 1210, 16, 562, 6204, 562, 18, 144, 5148, 8866, 8866, 5148, 144, 18, 162, 2912, 14014, 23166
OFFSET
0,1
LINKS
FORMULA
a(n) = 2*A051472(n). - G. C. Greubel, Jan 06 2024
EXAMPLE
Even elements of A028313 as an irregular triangle:
6, 6;
12;
8, 8;
38;
10, 36, 36, 10;
46, 130, 46;
12, 12;
...
MATHEMATICA
A028313[n_, k_]:= If[n<2, 1, Binomial[n, k] +3*Binomial[n-2, k-1]];
f= Table[A028313[n, k], {n, 0, 100}, {k, 0, n}]//Flatten;
b[n_]:= DeleteCases[{f[[n+1]]}, _?OddQ];
Table[b[n], {n, 0, 200}]//Flatten (* G. C. Greubel, Jan 06 2024 *)
PROG
(Magma)
A028313:= func< n, k | n le 1 select 1 else Binomial(n, k) +3*Binomial(n-2, k-1) >;
a:=[A028313(n, k): k in [0..n], n in [0..100]];
[a[n]: n in [1..200] | (a[n] mod 2) eq 0]; // G. C. Greubel, Jan 06 2024
(SageMath)
def A028313(n, k): return 1 if n<2 else binomial(n, k) + 3*binomial(n-2, k-1)
a=flatten([[A028313(n, k) for k in range(n+1)] for n in range(101)])
[a[n] for n in (0..200) if a[n]%2==0] # G. C. Greubel, Jan 06 2024
CROSSREFS
Sequence in context: A255488 A247513 A124508 * A220435 A340512 A338992
KEYWORD
nonn,tabf
EXTENSIONS
More terms from James A. Sellers
STATUS
approved