login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A173475
Triangle T(n, k) = c(n)/(c(k)*c(n-k)) where c(n) = Product_{j=0..n} A051179(j), read by rows.
1
1, 1, 1, 1, 5, 1, 1, 85, 85, 1, 1, 21845, 371365, 21845, 1, 1, 1431655765, 6254904037285, 6254904037285, 1431655765, 1, 1, 6148914691236517205, 1760625833240390967011987365, 452480839142780478522080752805, 1760625833240390967011987365, 6148914691236517205, 1
OFFSET
0,5
FORMULA
T(n, k) = c(n)/(c(k)*c(n-k)) where c(n) = Product_{j,0,n} A051179(j).
EXAMPLE
Triangle begins as:
1;
1, 1;
1, 5, 1;
1, 85, 85, 1;
1, 21845, 371365, 21845, 1;
1, 1431655765, 6254904037285, 6254904037285, 1431655765, 1;
MATHEMATICA
c[n_]:= Product[2^(2^j) - 1, {j, 0, n}];
T[n_, k_]:= c[n]/(c[k]*c[n-k]);
Table[T[n, k], {n, 0, 8}, {k, 0, n}]//Flatten
PROG
(Sage)
@CachedFunction
def c(n): return product( 2^(2^j) -1 for j in (0..n) )
def T(n, k): return c(n)/(c(k)*c(n-k))
flatten([[T(n, k) for k in (0..n)] for n in (0..8)]) # G. C. Greubel, Apr 26 2021
CROSSREFS
Cf. A051179.
Sequence in context: A111820 A174912 A106238 * A174919 A156952 A158748
KEYWORD
nonn,tabl,less
AUTHOR
Roger L. Bagula, Feb 19 2010
EXTENSIONS
Edited by G. C. Greubel, Apr 26 2021
STATUS
approved