login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A020740 Max_{k=0..n} d(C(n,k)) - d(C(n,[ n/2 ])), where d() = number of divisors. 2

%I #8 Oct 15 2013 22:30:16

%S 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,12,16,32,0,0,0,64,48,0,0,96,0,0,0,

%T 192,256,0,256,384,0,0,0,0,0,832,768,512,0,0,0,0,384,576,1536,3072,

%U 2048,8448,7680,5632,0,0,0,14336,3584,0,0,3072

%N Max_{k=0..n} d(C(n,k)) - d(C(n,[ n/2 ])), where d() = number of divisors.

%e n=20, d(C[ 20,10 ])= 48 and the d(C[ 20,k ]) values are 1,6,8,16,24,40,64,80. The maximum is 80, so the difference is 80-48 = 32.

%t Table[Max[Table[DivisorSigma[0,Binomial[n,k]],{k,0,n}]] - DivisorSigma[ 0,Binomial[n,Floor[n/2]]],{n,70}] (* _Harvey P. Dale_, Jul 18 2013 *)

%Y Cf. A000005, A048485, A048569.

%K nonn

%O 1,18

%A _Labos Elemer_

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 4 17:24 EDT 2024. Contains 372257 sequences. (Running on oeis4.)