login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A038234 Triangle whose (i,j)-th entry is binomial(i,j)*4^(i-j)*4^j. 1
1, 4, 4, 16, 32, 16, 64, 192, 192, 64, 256, 1024, 1536, 1024, 256, 1024, 5120, 10240, 10240, 5120, 1024, 4096, 24576, 61440, 81920, 61440, 24576, 4096, 16384, 114688, 344064, 573440, 573440, 344064, 114688, 16384, 65536, 524288 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Also the absolute values of the coefficients of the Belyi Polynomial P_(i,i)(x). - R. J. Mathar, Oct 16 2008

LINKS

Table of n, a(n) for n=0..37.

I. Bauer, F. Catanese, F. Grunewald, Chebycheff and Belyi Polynomials, Dessins de'Enfants, Beauville Surfaces and Group Theory, Med. J. Math. vol 3 no 2 (2006) 121-146. [From R. J. Mathar, Oct 16 2008]

B. N. Cyvin et al., Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons, Match, No. 34 (Oct 1996), pp. 109-121.

FORMULA

G.f.: 1/(1 - 4*x - 4*x*y). - Ilya Gutkovskiy, Apr 21 2017

EXAMPLE

1 ;

4 4 ;

16 32 16 ;

64 192 192 64 ;

256 1024 1536 1024 256 ;

1024 5120 10240 10240 5120 1024 ;

4096 24576 61440 81920 61440 24576 4096 ;

16384 114688 344064 573440 573440 344064 114688 16384 ;

65536 524288 1835008 3670016 4587520 3670016 1835008 524288 65536 ;

262144 2359296 9437184 22020096 33030144 33030144 22020096 9437184 2359296 262144 ;

CROSSREFS

Sequence in context: A183433 A322039 A158101 * A099462 A218051 A092266

Adjacent sequences:  A038231 A038232 A038233 * A038235 A038236 A038237

KEYWORD

nonn,tabl,easy

AUTHOR

N. J. A. Sloane.

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 6 05:18 EDT 2021. Contains 343580 sequences. (Running on oeis4.)