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 1-6 of 6 results.

A111538 Column 2 of triangle A111536; also equals column 0 of triangle A111541, which is the matrix log of triangle A111536.

Original entry on oeis.org

1, 3, 14, 84, 600, 4908, 44952, 454344, 5016768, 60062352, 775089312, 10728930912, 158638465536, 2496437377728, 41674737264000, 735831528563328, 13704461848753152, 268562085051533568, 5525005742876244480
Offset: 0

Views

Author

Paul D. Hanna, Aug 06 2005

Keywords

Crossrefs

Cf. A111536, A111541.

Programs

  • PARI
    {a(n)=if(n<0,0,(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+1)!/1!*x^i)),m-j-1))))^-1)[n+3,3])}

Formula

a(n) = A111536(n+2, 2) = A111541(n+1, 0).

A111542 Column 1 of triangle A111541, which is the matrix logarithm of A111536.

Original entry on oeis.org

0, 2, 5, 22, 128, 896, 7220, 65336, 653720, 7155104, 84998768, 1089232160, 14981704736, 220233312896, 3447195190592, 57261708795776, 1006401042534272, 18663532970127872, 364283224523605760, 7466218532765196800
Offset: 0

Views

Author

Paul D. Hanna, Aug 06 2005

Keywords

Comments

Column 0 of triangle A111541 is A111536.

Crossrefs

Cf. A111541 (triangle), A111538 (column 0), A111543 (column 2), A111536.

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+1)!/1!*x^i)),m-j-1))))); if(n<0,0,sum(i=1,#M,(M^0-M)^i/i)[n+2,2])}

A111543 Column 2 of triangle A111541, which is the matrix logarithm of A111536.

Original entry on oeis.org

0, 3, 8, 36, 212, 1496, 12128, 110288, 1108064, 12171872, 145061120, 1864321472, 25710635648, 378871778432, 5943632568320, 98936446059776, 1742232571097600, 32367994818881024, 632845309575139328, 12991224275641441280
Offset: 0

Views

Author

Paul D. Hanna, Aug 06 2005

Keywords

Crossrefs

Cf. A111541 (triangle), A111538 (column 0), A111542 (column 1), A111536.

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+1)!/1!*x^i)),m-j-1))))); if(n<0,0,sum(i=1,#M,(M^0-M)^i/i)[n+3,3])}

A111536 Triangular matrix T, read by rows, that satisfies: SHIFT_LEFT(column 0 of T^p) = p*(column p+2 of T), or [T^p](m,0) = p*T(p+m,p+2) for all m>=1 and p>=-2.

Original entry on oeis.org

1, 1, 1, 4, 2, 1, 22, 8, 3, 1, 148, 44, 14, 4, 1, 1156, 296, 84, 22, 5, 1, 10192, 2312, 600, 148, 32, 6, 1, 99688, 20384, 4908, 1156, 242, 44, 7, 1, 1069168, 199376, 44952, 10192, 2084, 372, 58, 8, 1, 12468208, 2138336, 454344, 99688, 20012, 3528, 544, 74, 9, 1
Offset: 0

Views

Author

Paul D. Hanna, Aug 06 2005

Keywords

Comments

Column 0 equals A111529 (related to log of factorial series).
Column 2 (A111538) equals SHIFT_LEFT(column 0 of log(T)), where the matrix logarithm, log(T), equals the integer matrix A111541.

Examples

			SHIFT_LEFT(column 0 of T^-2) = -2*(column 0 of T);
SHIFT_LEFT(column 0 of T^-1) = -1*(column 1 of T);
SHIFT_LEFT(column 0 of log(T)) = column 2 of T;
SHIFT_LEFT(column 0 of T^1) = 1*(column 3 of T);
SHIFT_LEFT(column 0 of T^2) = 2*(column 4 of T);
where SHIFT_LEFT of column sequence shifts 1 place left.
Triangle T begins:
1;
1, 1;
4, 2, 1;
22, 8, 3, 1;
148, 44, 14, 4, 1;
1156, 296, 84, 22, 5, 1;
10192, 2312, 600, 148, 32, 6, 1;
99688, 20384, 4908, 1156, 242, 44, 7, 1;
1069168, 199376, 44952, 10192, 2084, 372, 58, 8, 1;
12468208, 2138336, 454344, 99688, 20012, 3528, 544, 74, 9, 1; ...
...
After initial term, column 1 is twice column 0.
Matrix inverse T^-1 = A111540 starts:
1;
-1, 1;
-2, -2, 1;
-8, -2, -3, 1;
-44, -8, -2, -4, 1;
-296, -44, -8, -2, -5, 1;
-2312, -296, -44, -8, -2, -6, 1;
-20384, -2312, -296, -44, -8, -2, -7, 1;
-199376, -20384, -2312, -296, -44, -8, -2, -8, 1; ...
where columns are all equal after initial terms;
compare columns of T^-1 to column 1 of T.
Matrix logarithm log(T) = A111541 is:
0;
1, 0;
3, 2, 0;
14, 5, 3, 0;
84, 22, 8, 4, 0;
600, 128, 36, 12, 5, 0;
4908, 896, 212, 58, 17, 6, 0;
44952, 7220, 1496, 360, 90, 23, 7, 0;
454344, 65336, 12128, 2652, 602, 134, 30, 8, 0;
5016768, 653720, 110288, 22320, 4736, 974, 192, 38, 9, 0; ...
compare column 0 of log(T) to column 2 of T.

Links

Crossrefs

Cf. A111537 (column 1), A111538 (column 2), A111539 (row sums), A111540 (matrix inverse), A111541 (matrix log); related tables: A111528, A104980, A111544, A111553.

Programs

  • Mathematica
    T[n_, k_] := T[n, k] = If[nJean-François Alcover, Jan 24 2017, adapted 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+1, 1)*T(n, j+k+1) for n>k>0, with T(n, n) = 1, T(n+1, n) = n+1, T(n+2, 1) = 2*T(n+1, 0), T(n+3, 3) = T(n+1, 0), for n>=0.

A111549 Matrix logarithm of triangle A111544.

Original entry on oeis.org

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, 136863, 17016, 2607, 486, 103, 24, 7, 0, 1562715, 176112, 24099, 3990, 747, 148, 31, 8, 0, 19301319, 1993392, 247527, 37182, 6351, 1140, 207, 39, 9, 0
Offset: 0

Views

Author

Paul D. Hanna, Aug 07 2005

Keywords

Comments

Column 0 (A111546) is found in column 3 of triangle A111544.

Examples

			Triangle begins:
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;
136863,17016,2607,486,103,24,7,0;
1562715,176112,24099,3990,747,148,31,8,0; ...

Crossrefs

Cf. A111544, A111546, A111541.

Programs

  • PARI
    {T(n,k)=local(M=matrix(n+1,n+1,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))))); sum(i=1,#M,(M^0-M)^i/i)[n+1,k+1]}

Formula

T(n+1, 0) = A111546(n) = A111544(n+3, 3).

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

Cf. A111553, A111557, A104986, A111541, A111549.

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 1-6 of 6 results.

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