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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A185624 Triangle, read by rows, equal to the matrix square of triangle A185620. 6
 1, 2, 1, 3, 2, 1, 6, 7, 2, 1, 18, 28, 11, 2, 1, 79, 142, 66, 15, 2, 1, 463, 913, 470, 120, 19, 2, 1, 3396, 7244, 3997, 1098, 190, 23, 2, 1, 30073, 69004, 40079, 11587, 2122, 276, 27, 2, 1, 314037, 771359, 466448, 140092, 26707, 3638, 378, 31, 2, 1, 3796561, 9933242, 6208551, 1921122 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS EXAMPLE Triangle begins: 1; 2, 1; 3, 2, 1; 6, 7, 2, 1; 18, 28, 11, 2, 1; 79, 142, 66, 15, 2, 1; 463, 913, 470, 120, 19, 2, 1; 3396, 7244, 3997, 1098, 190, 23, 2, 1; 30073, 69004, 40079, 11587, 2122, 276, 27, 2, 1; 314037, 771359, 466448, 140092, 26707, 3638, 378, 31, 2, 1; 3796561, 9933242, 6208551, 1921122, 377495, 53149, 5742, 496, 35, 2, 1; ... This triangle equals the matrix square, R^2, of triangle R = A185620, which begins: 1; 1, 1; 1, 1, 1; 1, 3, 1, 1; 1, 10, 5, 1, 1; 1, 42, 27, 7, 1, 1; 1, 226, 173, 52, 9, 1, 1; 1, 1525, 1330, 442, 85, 11, 1, 1; 1, 12555, 12134, 4345, 897, 126, 13, 1, 1; ... where R^3 - R^2 + I equals R shifted left one column. PROG (PARI) {T(n, k)=local(A=Mat(1), B); for(m=1, n, B=A^3-A^2+A^0; A=matrix(m+1, m+1); for(i=1, m+1, for(j=1, i, if(i<2|j==i, A[i, j]=1, if(j==1, A[i, j]=1, A[i, j]=B[i-1, j-1]))))); return((A^2)[n+1, k+1])} CROSSREFS Cf. A185620, A185625, A185626, A185627, A185628. Sequence in context: A054098 A132089 A321155 * A162387 A107880 A102228 Adjacent sequences: A185621 A185622 A185623 * A185625 A185626 A185627 KEYWORD nonn,tabl AUTHOR Paul D. Hanna, Sep 07 2011 STATUS approved

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.

Last modified March 22 04:35 EDT 2023. Contains 361413 sequences. (Running on oeis4.)