Svoboda | Graniru | BBC Russia | Golosameriki | Facebook
login
A172196
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, 17, 1, 1, 481, 481, 1, 1, 106177, 97345, 106177, 1, 1, 98421121, 95179393, 95179393, 98421121, 1, 1, 384472892161, 378269256961, 378490726657, 378269256961, 384472892161, 1, 1, 6152325140989441, 6103497476160001, 6104283149099521, 6104283149099521, 6103497476160001, 6152325140989441, 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 = 2.
EXAMPLE
Triangle begins as:
1;
1, 1;
1, 17, 1;
1, 481, 481, 1;
1, 106177, 97345, 106177, 1;
1, 98421121, 95179393, 95179393, 98421121, 1;
1, 384472892161, 378269256961, 378490726657, 378269256961, 384472892161, 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, 2], {n, 0, 10}, {k, 0, n}]//Flatten (* 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, 2): 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))
flatten([[T(n, k, 2) for k in (0..n)] for n in (0..10)]) # G. C. Greubel, May 06 2021
CROSSREFS
Cf. this sequence (q=2), A172198 (q=3).
Sequence in context: A022180 A156581 A015143 * A056110 A040296 A040297
KEYWORD
nonn,tabl,less,easy
AUTHOR
Roger L. Bagula, Jan 29 2010
EXTENSIONS
Edited by G. C. Greubel, May 06 2021
STATUS
approved