login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A185095 Rectangular array read by antidiagonals: row q has generating function F_q(x) = sum_{r=0,...,q-1} ((q-r)*(-1)^r*binomial(2*q-r,r)*x^r) / sum_{s=0,...,q} ((-1)^s*binomial(2*q-s,s)*x^s), where q=1,2,.... 5

%I #44 Nov 30 2014 02:52:38

%S 1,2,1,3,3,1,4,5,7,1,5,7,13,18,1,6,9,19,38,47,1,7,11,25,58,117,123,1,

%T 8,13,31,78,187,370,322,1,9,15,37,98,257,622,1186,843,1,10,17,43,118,

%U 327,874,2110,3827,2207,1,11,19,49,138,397,1126,3034,7252,12389,5778,1

%N Rectangular array read by antidiagonals: row q has generating function F_q(x) = sum_{r=0,...,q-1} ((q-r)*(-1)^r*binomial(2*q-r,r)*x^r) / sum_{s=0,...,q} ((-1)^s*binomial(2*q-s,s)*x^s), where q=1,2,....

%C Row indices q begin with 1, column indices n begin with 0.

%H S. Barbero, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL17/Barbero/barbero15.html">Dickson Polynomials, Chebyshev Polynomials, and Some Conjectures of Jeffery</a>, Journal of Integer Sequences, 17 (2014), #14.3.8.

%F Conjecture. The n-th entry in row q is given by R_q(n) = 2^(2*n)*(sum_{j=1,...,n+1} (cos(j*Pi/(2*q+1)))^(2*n)), q >= 1, n >= 0.

%F Conjecture. G.f. for column n is of the form G_n(x) = H_n(x)/(1-x)^2, where H_n(x) is a polynomial in x, n >= 0.

%F Conjecture. 2*A185095(q,n) = A198632(2*q,n), q >= 1, n >= 0. - _L. Edson Jeffery_, Nov 23 2013

%e Array begins as

%e 1, 1, 1, 1, 1, 1, ...

%e 2, 3, 7, 18, 47, 123, ...

%e 3, 5, 13, 38, 117, 370, ...

%e 4, 7, 19, 58, 187, 622, ...

%e 5, 9, 25, 78, 257, 874, ...

%e 6, 11, 31, 98, 327, 1126, ...

%e ...

%Y Conjecture. Transpose of array A186740.

%Y Conjecture. Rows 0,1,2 (up to an offset) are A000012, A005248, A198636 (proved, see the Barbero, et al., reference there).

%Y Conjecture. Columns 0,1,2,3,4 (up to an offset) are A000027, A005408, A016921, A114698, A114646.

%Y Cf. A209235.

%K nonn,tabl

%O 0,2

%A _L. Edson Jeffery_, Jan 23 2012

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 04:05 EDT 2024. Contains 371235 sequences. (Running on oeis4.)