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A106728
Triangle T(n, k) = ( ((f(n+1) mod 5) mod 4) + ((f(k+1) mod 5) mod 4) ) mod 4, where f(n) = 10 - (prime(n+3) mod 10).
1
2, 3, 0, 1, 2, 0, 2, 3, 1, 2, 0, 1, 3, 0, 2, 1, 2, 0, 1, 3, 0, 0, 1, 3, 0, 2, 3, 2, 3, 0, 2, 3, 1, 2, 1, 0, 2, 3, 1, 2, 0, 1, 0, 3, 2, 3, 0, 2, 3, 1, 2, 1, 0, 3, 0, 1, 2, 0, 1, 3, 0, 3, 2, 1, 2, 0, 2, 3, 1, 2, 0, 1, 0, 3, 2, 3, 1, 2, 1, 2, 0, 1, 3, 0, 3, 2, 1, 2, 0, 1, 0, 0, 1, 3, 0, 2, 3, 2, 1, 0, 1, 3, 0, 3, 2
OFFSET
0,1
FORMULA
T(n, k) = ( ((f(n+1) mod 5) mod 4) + ((f(k+1) mod 5) mod 4) ) mod 4, where f(n) = 10 - (prime(n+3) mod 10).
EXAMPLE
Triangle begins as:
2;
3, 0;
1, 2, 0;
2, 3, 1, 2;
0, 1, 3, 0, 2;
1, 2, 0, 1, 3, 0;
0, 1, 3, 0, 2, 3, 2;
3, 0, 2, 3, 1, 2, 1, 0;
2, 3, 1, 2, 0, 1, 0, 3, 2;
3, 0, 2, 3, 1, 2, 1, 0, 3, 0;
1, 2, 0, 1, 3, 0, 3, 2, 1, 2, 0;
MATHEMATICA
f[n_]= 10 -Mod[Prime[n+3], 10];
T[n_, k_]:= Mod[Mod[Mod[f[n+1], 5], 4] + Mod[Mod[f[k+1], 5], 4], 4];
Table[T[n, k], {n, 0, 15}, {k, 0, n}]//Flatten
PROG
(Sage)
def f(n): return 10 - (nth_prime(n+3)%10)
def A106728(n, k): return ( ((f(n+1))%5)%4 + ((f(k+1))%5)%4 )%4
flatten([[A106728(n, k) for k in (0..n)] for n in (0..15)]) # G. C. Greubel, Sep 10 2021
CROSSREFS
Cf. A106727.
Sequence in context: A271369 A308322 A308898 * A292603 A308880 A319047
KEYWORD
nonn,tabl,easy,less
AUTHOR
Roger L. Bagula, May 14 2005
EXTENSIONS
Edited by G. C. Greubel, Sep 10 2021
STATUS
approved