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

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A098384 Triangle read by rows of coefficients used to generate diagonals of ordered factorizations as displayed in A098348. 2
1, 3, 2, 13, 18, 8, 75, 158, 144, 48, 541, 1530, 2120, 1440, 384, 4683, 16622, 30960, 31920, 17280, 3840 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Note that the table includes the well-known sequence (A000165) discussed by Gordon on pages 636-645 of AMM 106 (1999).

LINKS

Table of n, a(n) for n=0..20.

FORMULA

From Peter Bala, Apr 20 2012: (Start)

The following formulas are all conjectural:

T(n,k) = 2^k*sum {i = k+1..n+1} binomial(i,k+1)*(i-1)!*Stirling2(n+1,i) = 1/(k+1)*A194649(n+1,k).

Recurrence equation:

T(n,k) = 2*k*T(n-1,k-1) + 3*(k+1)*T(n-1,k) + (k+2)*T(n-1,k+1).

E.g.f.: exp(x)/((2-exp(x))*(2*t+2-(2*t+1)*exp(x))) = 1 + (3+2*t)*x + (13+18*t+8*t^2)*x^2/2! + ....

Column n generating function: 2^n*exp(x)*(1-exp(x))^n/(exp(x)-2)^(n+2) for n >= 0.

(End)

EXAMPLE

The table begins:

1

3 2

13 18 8

75 158 144 48

541 1530 2120 1440 384

The binomial transform of (13,18,8) yields 13,31,57,91,...

The binomial transform of 13,31,57,91,... yields 13,44,132,368,... A098385

CROSSREFS

Cf. A000165, A052876, A098348, A098385. A194649.

Sequence in context: A095131 A060149 A059374 * A243253 A064536 A231183

Adjacent sequences:  A098381 A098382 A098383 * A098385 A098386 A098387

KEYWORD

nonn,tabl

AUTHOR

Alford Arnold, Sep 06 2004

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified December 9 23:16 EST 2016. Contains 278993 sequences.