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.

A144339 Second column (m=2) of triangle S2hat(-4) = A144285.

Original entry on oeis.org

1, 4, 52, 648, 12888, 286272, 8182944, 266366016, 10191545280, 437925035520, 21158411936256, 1127285473434624, 65884689657464832, 4181915450891501568, 286704379021188538368, 21099339893878107144192, 1659252422924430692327424, 138827012602215571388891136
Offset: 0

Views

Author

Wolfdieter Lang, Oct 09 2008

Keywords

Crossrefs

Cf. A144285, A008546 (m=1 column), A144340 (m=3 column).

Formula

a(n) = A144285(n+2,2), n>=0.

A144340 Third column (m=3) of triangle S2hat(-4) = A144285.

Original entry on oeis.org

1, 4, 52, 712, 13464, 299520, 8455392, 273091392, 10372138560, 443940231168, 21373226590464, 1136301643620864, 66301616889414144, 4203565310173630464, 287934809159520681984, 21176025476308764622848, 1664420505612432224993280, 139202656243140427345723392
Offset: 0

Views

Author

Wolfdieter Lang Oct 09 2008

Keywords

Crossrefs

A144339 (m=2 column).

Formula

a(n)=A144285(n+3,3), n>=0.

A144286 Row sums of triangle A144285 (called S2hat(-4)).

Original entry on oeis.org

1, 5, 41, 561, 10281, 243481, 6965401, 235103417, 9112789817, 399330154617, 19502558109177, 1050527843743993, 61855087724349433, 3952225158444979193, 272326955744655069689, 20128716335079745234425, 1588573078022351774367225, 133323969310853649963402745
Offset: 1

Views

Author

Wolfdieter Lang, Oct 09 2008

Keywords

Crossrefs

Cf. A144285.

Formula

a(n) = Sum_{m=1..n} A144285(n,m), n>=1.

A144342 Lower triangular array called S2hat(-5) related to partition number array A144341.

Original entry on oeis.org

1, 5, 1, 55, 5, 1, 935, 80, 5, 1, 21505, 1210, 80, 5, 1, 623645, 29205, 1335, 80, 5, 1, 21827575, 782595, 30580, 1335, 80, 5, 1, 894930575, 27002800, 821095, 31205, 1335, 80, 5, 1, 42061737025, 1058476100, 27963925, 827970, 31205, 1335, 80, 5, 1, 2229272062325, 48782479625
Offset: 1

Views

Author

Wolfdieter Lang Oct 09 2008

Keywords

Comments

If in the partition array M32khat(-5)= A144341 entries with the same parts number m are summed one obtains this triangle of numbers S2hat(-5). In the same way the Stirling2 triangle A008277 is obtained from the partition array M_3 = A036040.
The first three columns are A008543, A144344, A144345.

Examples

			[1];[5,1];[55,5,1];[935,80,5,1];[21505,1210,80,5,1];...
		

Crossrefs

Row sums A144343.
A144285 (S2hat(-4)).

Formula

a(n,m)=sum(product(|S2(-5;j,1)|^e(n,m,q,j),j=1..n),q=1..p(n,m)) if n>=m>=1, else 0. Here p(n,m)=A008284(n,m), the number of m parts partitions of n and e(n,m,q,j) is the exponent of j in the q-th m part partition of n. |S2(-5,n,1)|= A013988(n,1) = A008543(n-1) = (6*n-7)(!^6) (6-factorials) for n>=2 and 1 if n=1.

A144284 Partition number array, called M32hat(-4)= 'M32(-4)/M3'= 'A144267/A036040', related to A011801(n,m)= |S2(-4;n,m)| (generalized Stirling triangle).

Original entry on oeis.org

1, 4, 1, 36, 4, 1, 504, 36, 16, 4, 1, 9576, 504, 144, 36, 16, 4, 1, 229824, 9576, 2016, 1296, 504, 144, 64, 36, 16, 4, 1, 6664896, 229824, 38304, 18144, 9576, 2016, 1296, 576, 504, 144, 64, 36, 16, 4, 1, 226606464, 6664896, 919296, 344736, 254016, 229824, 38304, 18144
Offset: 1

Views

Author

Wolfdieter Lang Oct 09 2008

Keywords

Comments

Each partition of n, ordered as in Abramowitz-Stegun (A-St order; for the reference see A134278), is mapped to a nonnegative integer a(n,k) =: M32hat(-4;n,k) with the k-th partition of n in A-St order.
The sequence of row lengths is A000041 (partition numbers) [1, 2, 3, 5, 7, 11, 15, 22, 30, 42,...].
If M32hat(-4;n,k) is summed over those k with fixed number of parts m one obtains triangle S2hat(-4):= A144285(n,m).

Examples

			a(4,3)= 16 = |S2(-4,2,1)|^2. The relevant partition of 4 is (2^2).
		

Crossrefs

A144279 (M32hat(-3) array). A144341 (M32hat(-5) array)

Formula

a(n,k)= product(|S2(-4,j,1)|^e(n,k,j),j=1..n) with |S2(-4,n,1)|= A008546(n-1) = (5*n-6)(!^5) (5-factorials) for n>=2 and 1 if n=1 and the exponent e(n,k,j) of j in the k-th partition of n in the A-St ordering of the partitions of n.
Formally a(n,k)= 'M32(-4)/M3' = 'A144267/A036040' (elementwise division of arrays).
Showing 1-5 of 5 results.