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!)
A172355 Triangle t(n,k) read by rows: generalized Padovan factorial ratios c(n)/(c(k)*c(n-k)) where c are partial products of a generalized Padovan sequence with multiplier m=5. 1

%I #5 Jul 05 2012 12:06:24

%S 1,1,1,1,1,1,1,5,5,1,1,6,30,6,1,1,26,156,156,26,1,1,35,910,1092,910,

%T 35,1,1,136,4760,24752,24752,4760,136,1,1,201,27336,191352,829192,

%U 191352,27336,201,1,1,715,143715,3909048,22802780,22802780,3909048,143715,715

%N Triangle t(n,k) read by rows: generalized Padovan factorial ratios c(n)/(c(k)*c(n-k)) where c are partial products of a generalized Padovan sequence with multiplier m=5.

%C Start from the generalized Padovan sequence f(n) = 0, 1, 1, 5, 6, 26, 35, 136, 201, 715, 1141, 3776,.. , f(n) = 5*f(n-2)+f(n-3), and its partial products c(n) = 1, 1, 1, 5, 30, 780, 27300, 3712800, 746272800, 533585052000.. Then t(n,k) = c(n)/(c(k)*c(n-k)).

%C Row sums are 1, 2, 3, 12, 44, 366, 2984, 59298, 1266972, 53712518, 2554657926,....

%C Note that rows n>= 14 contain fractions. - _R. J. Mathar_, Jul 05 2012

%e 1;

%e 1, 1;

%e 1, 1, 1;

%e 1, 5, 5, 1;

%e 1, 6, 30, 6, 1;

%e 1, 26, 156, 156, 26, 1;

%e 1, 35, 910, 1092, 910, 35, 1;

%e 1, 136, 4760, 24752, 24752, 4760, 136, 1;

%e 1, 201, 27336, 191352, 829192, 191352, 27336, 201, 1;

%e 1, 715, 143715, 3909048, 22802780, 22802780, 3909048, 143715, 715, 1;

%e 1, 1141, 815815, 32795763, 743370628, 1000691230, 743370628, 32795763, 815815, 1141, 1;

%t Clear[f, c, a, t];

%t f[0, a_] := 0; f[1, a_] := 1; f[2, a_] := 1;

%t f[n_, a_] := f[n, a] = a*f[n - 2, a] + f[n - 3, a];

%t c[n_, a_] := If[n == 0, 1, Product[f[i, a], {i, 1, n}]];

%t t[n_, m_, a_] := c[n, a]/(c[m, a]*c[n - m, a]);

%t Table[Table[Table[t[n, m, a], {m, 0, n}], {n, 0, 10}], {a, 1, 10}];

%t Table[Flatten[Table[Table[t[n, m, a], {m, 0, n}], {n, 0, 10}]], {a, 1, 10}]

%Y Cf. A010048, A172353

%K nonn,tabl,less

%O 0,8

%A _Roger L. Bagula_, Feb 01 2010

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 September 13 00:40 EDT 2024. Contains 375857 sequences. (Running on oeis4.)