The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A115512 Number triangle (1,x)+(x,x^3) expressed in terms of Riordan arrays. 1

%I

%S 1,1,1,0,0,1,0,0,0,1,0,1,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,1,0,0,0,

%T 0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,1,0,0,

%U 0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,0,1

%N Number triangle (1,x)+(x,x^3) expressed in terms of Riordan arrays.

%C Row sums are periodic {1,2,1}. Diagonal sums are periodic {1,1,1,0}. Inverse is A115513.

%F Column k has g.f. x^k+x^(3k+1); Number triangle T(n, k)=if(n=k, 1, 0) OR if(n=3k+1, 1, 0).

%e Triangle begins

%e 1,

%e 1, 1,

%e 0, 0, 1,

%e 0, 0, 0, 1,

%e 0, 1, 0, 0, 1,

%e 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 1, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1

%K easy,nonn,tabl

%O 0,1

%A _Paul Barry_, Jan 23 2006

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

Last modified July 25 10:46 EDT 2021. Contains 346289 sequences. (Running on oeis4.)