cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-5 of 5 results.

A111547 Column 3 of triangle A111544; also found in column 0 of triangle A111549, which equals the matrix logarithm of A111544.

Original entry on oeis.org

1, 4, 23, 165, 1383, 13083, 136863, 1562715, 19301319, 256191363, 3636036783, 54956529675, 881578601559, 14964805041363, 268105552191423, 5057384615702235, 100224731537223399, 2082402995330965923
Offset: 0

Views

Author

Paul D. Hanna, Aug 07 2005

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=if(n<0,0,(matrix(n+4,n+4,m,j,if(m==j,1,if(m==j+1,-m+1, -(m-j-1)*polcoeff(log(sum(i=0,m,(i+2)!/2!*x^i)),m-j-1))))^-1)[n+4,4])}

Formula

a(n) = A111544(n+3, 3) = A111549(n+1, 0).

A111550 Column 1 of A111549, which is the matrix log of A111544.

Original entry on oeis.org

0, 2, 6, 32, 222, 1824, 17016, 176112, 1993392, 24438960, 322294896, 4548010032, 68385367152, 1091838106800, 18454096189296, 329306074785072, 6189015238217712, 122232512688657840, 2531600753529542256
Offset: 0

Views

Author

Paul D. Hanna, Aug 07 2005

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=local(M=matrix(n+2,n+2,m,j,if(m==j,1,if(m==j+1,-m+1, -(m-j-1)*polcoeff(log(sum(i=0,m,(i+2)!/2!*x^i)),m-j-1))))); if(n<0,0,sum(i=1,#M,(M^0-M)^i/i)[n+2,2])}

A111551 Column 2 of A111549, which is the matrix log of A111544.

Original entry on oeis.org

0, 3, 9, 47, 321, 2607, 24099, 247527, 2783331, 33924303, 445016619, 6249234807, 93541817331, 1487200667103, 25037315924859, 445123900236807, 8336458657796931, 164100631571947503, 3388128151043405259
Offset: 0

Views

Author

Paul D. Hanna, Aug 07 2005

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=local(M=matrix(n+3,n+3,m,j,if(m==j,1,if(m==j+1,-m+1, -(m-j-1)*polcoeff(log(sum(i=0,m,(i+2)!/2!*x^i)),m-j-1))))); if(n<0,0,sum(i=1,#M,(M^0-M)^i/i)[n+3,3])}

A111544 Triangular matrix T, read by rows, that satisfies: SHIFT_LEFT(column 0 of T^p) = p*(column p+3 of T), or [T^p](m,0) = p*T(p+m,p+3) for all m>=1 and p>=-3.

Original entry on oeis.org

1, 1, 1, 5, 2, 1, 33, 9, 3, 1, 261, 57, 15, 4, 1, 2361, 441, 99, 23, 5, 1, 23805, 3933, 783, 165, 33, 6, 1, 263313, 39249, 7083, 1383, 261, 45, 7, 1, 3161781, 430677, 71415, 13083, 2361, 393, 59, 8, 1, 40907241, 5137641, 789939, 136863, 23805, 3861, 567, 75, 9, 1
Offset: 0

Views

Author

Paul D. Hanna, Aug 07 2005

Keywords

Comments

Column 0 equals A111530 (related to log of factorial series). Column 3 (A111547) equals SHIFT_LEFT(column 0 of log(T)), where the matrix logarithm, log(T), equals the integer matrix A111549.

Examples

			SHIFT_LEFT(column 0 of T^-3) = -3*(column 0 of T);
SHIFT_LEFT(column 0 of T^-2) = -2*(column 1 of T);
SHIFT_LEFT(column 0 of T^-1) = -1*(column 2 of T);
SHIFT_LEFT(column 0 of log(T)) = column 3 of T;
SHIFT_LEFT(column 0 of T^1) = 1*(column 4 of T);
where SHIFT_LEFT of column sequence shifts 1 place left.
Triangle T begins:
1;
1,1;
5,2,1;
33,9,3,1;
261,57,15,4,1;
2361,441,99,23,5,1;
23805,3933,783,165,33,6,1;
263313,39249,7083,1383,261,45,7,1;
3161781,430677,71415,13083,2361,393,59,8,1; ...
After initial term, column 2 is 3 times column 0.
Matrix inverse T^-1 = A111548 starts:
1;
-1,1;
-3,-2,1;
-15,-3,-3,1;
-99,-15,-3,-4,1;
-783,-99,-15,-3,-5,1;
-7083,-783,-99,-15,-3,-6,1; ...
where columns are all equal after initial terms;
compare columns of T^-1 to column 2 of T.
Matrix logarithm log(T) = A111549 is:
0;
1,0;
4,2,0;
23,6,3,0;
165,32,9,4,0;
1383,222,47,13,5,0;
13083,1824,321,70,18,6,0; ...
compare column 0 of log(T) to column 3 of T.
		

Crossrefs

Cf. A111545 (column 1), A111546 (column 2), A111547 (column 3), A111552 (row sums), A111548 (matrix inverse), A111549 (matrix log); related tables: A111528, A104980, A111536, A111553.

Programs

  • Mathematica
    T[n_, k_] := T[n, k] = If[nJean-François Alcover, Aug 09 2018, from PARI *)
  • PARI
    T(n,k)=if(n
    				

Formula

T(n, k) = k*T(n, k+1) + Sum_{j=0..n-k-1} T(j+2, 2)*T(n, j+k+1) for n>k>0, with T(n, n) = 1, T(n+1, n) = n+1, T(n+3, 2) = 3*T(n+1, 0), T(n+4, 4) = T(n+1, 0), for n>=0.

A111560 Matrix logarithm of triangle A111553.

Original entry on oeis.org

0, 1, 0, 5, 2, 0, 34, 7, 3, 0, 282, 44, 10, 4, 0, 2696, 354, 60, 14, 5, 0, 28792, 3328, 470, 84, 19, 6, 0, 337072, 35144, 4344, 654, 118, 25, 7, 0, 4273632, 407984, 45320, 6008, 936, 164, 32, 8, 0, 58195072, 5137824, 521200, 62344, 8704, 1352, 224, 40, 9, 0
Offset: 0

Views

Author

Paul D. Hanna, Aug 07 2005

Keywords

Examples

			Triangle begins:
0;
1,0;
5,2,0;
34,7,3,0;
282,44,10,4,0;
2696,354,60,14,5,0;
28792,3328,470,84,19,6,0;
337072,35144,4344,654,118,25,7,0;
4273632,407984,45320,6008,936,164,32,8,0; ...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=local(M=matrix(n+2,n+2,m,j,if(m==j,1,if(m==j+1,-m+1, -(m-j-1)*polcoeff(log(sum(i=0,m,(i+3)!/3!*x^i)),m-j-1))))); sum(i=1,#M,(M^0-M)^i/i)[n+1,k+1]}
Showing 1-5 of 5 results.