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A172198
Triangle T(n, k, q) = 1 + abs(c(n,q) - c(k,q))*abs(c(n,q) - c(n-k, q)), where c(n,q) = Product_{j=1..n} (1 - q^j) and q = 2, read by rows.
2
1, 1, 1, 1, 325, 1, 1, 178849, 178849, 1, 1, 1121470273, 1106493697, 1121470273, 1, 1, 65131063096321, 64859828626945, 64859828626945, 65131063096321, 1, 1, 34423599076368353281, 34376183545107456001, 34376383642256188417, 34376183545107456001, 34423599076368353281, 1
OFFSET
0,5
FORMULA
T(n, k, q) = 1 + abs(c(n,q) - c(k,q))*abs(c(n,q) - c(n-k, q)), where c(n,q) = Product_{j=1..n} (1 - q^j) and q = 3.
EXAMPLE
Triangle begins as:
1;
1, 1;
1, 325, 1;
1, 178849, 178849, 1;
1, 1121470273, 1106493697, 1121470273, 1;
1, 65131063096321, 64859828626945, 64859828626945, 65131063096321, 1;
MATHEMATICA
T[n_, k_, q_]:= 1 + Abs[QPochhammer[q, q, n] -QPochhammer[q, q, k]]*Abs[QPochhammer[q, q, n] - QPochhammer[q, q, n-k]];
Table[T[n, k, 3], {n, 0, 10}, {k, 0, n}]//TableForm (* modified by G. C. Greubel, May 06 2021 *)
PROG
(Magma)
c:= func< n, q | n eq 0 select 1 else (&*[1-q^j: j in [1..n]]) >;
T:= func< n, k, q | 1 + Abs(c(n, q) - c(k, q))*Abs(c(n, q) - c(n-k, q)) >;
[T(n, k, 3): k in [0..n], n in [0..10]]; // G. C. Greubel, May 06 2021
(Sage)
from sage.combinat.q_analogues import q_pochhammer
def T(n, k, q): return 1 + abs(q_pochhammer(n, q, q) -q_pochhammer(k, q, q))*abs(q_pochhammer(n, q, q) -q_pochhammer(n-k, q, q))
[[T(n, k, 3) for k in (0..n)] for n in (0..10)] # G. C. Greubel, May 06 2021
CROSSREFS
Cf. A172196 (q=2), this sequence (q=3).
Sequence in context: A202635 A013763 A013887 * A343080 A159976 A253433
KEYWORD
nonn,tabl,less,easy
AUTHOR
Roger L. Bagula, Jan 29 2010
EXTENSIONS
Edited by G. C. Greubel, May 06 2021
STATUS
approved