login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A113387 Triangle, read by rows, equal to the matrix cube of A113381. 5
1, 6, 1, 48, 15, 1, 605, 255, 24, 1, 11196, 5630, 624, 33, 1, 280440, 159210, 19484, 1155, 42, 1, 8981460, 5584635, 731664, 46541, 1848, 51, 1, 353283128, 236051661, 32532732, 2173248, 91175, 2703, 60, 1, 16567072675, 11741443007, 1683566556 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,2

FORMULA

Column k of A113381^3 = column 0 of A113389^(3*k+2) for k>=0.

EXAMPLE

Triangle A113381^3 begins:

1;

6,1;

48,15,1;

605,255,24,1;

11196,5630,624,33,1;

280440,159210,19484,1155,42,1;

8981460,5584635,731664,46541,1848,51,1;

353283128,236051661,32532732,2173248,91175,2703,60,1;

16567072675,11741443007,1683566556,116647443,5086116,157760,3720,69,1;

PROG

(PARI) {T(n, k)=local(A, B); A=Mat(1); for(m=2, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(i<3|j==i|j>m-1, B[i, j]=1, if(j==1, B[i, 1]=1, B[i, j]=(A^(3*j-2))[i-j+1, 1])); )); A=B); (matrix(#A, #A, r, c, if(r>=c, (A^(3*c-1))[r-c+1, 1]))^3)[n+1, k+1]}

CROSSREFS

Cf. A113381, A113388 (column 0), A113389.

Sequence in context: A138192 A136235 A113392 * A090435 A136237 A083837

Adjacent sequences:  A113384 A113385 A113386 * A113388 A113389 A113390

KEYWORD

nonn,tabl

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Nov 14 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 20:03 EST 2012. Contains 205852 sequences.