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!)
A110756 a(n) = tau(N), where N = concatenation 1,2,3,...,n. 5
1, 6, 4, 4, 8, 28, 4, 24, 12, 8, 64, 32, 8, 8, 8, 12, 24, 48, 64, 192, 256, 64, 16, 48, 24, 160, 96, 64, 16, 128, 8, 48, 64, 4, 192, 120, 16, 16, 64, 384, 32, 128, 16, 48, 768, 128, 32, 192, 64, 768, 8, 32, 64, 1792, 32, 24, 64, 16, 16, 128, 8, 192, 24, 768, 64 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..65.

FORMULA

a(n) = A000005(A007908(n)). - R. J. Mathar, Feb 10 2007

EXAMPLE

a(3) = tau(123) = 4.

MAPLE

A055642 := proc(n) 1+floor(log10(n)) ; end; A000005 := proc(n) numtheory[tau](n) ; end ; A007908 := proc(n) local a ; a := 1 ; for i from 2 to n do a := a*10^A055642(i)+i ; end; RETURN(a) ; end; A110756 := proc(n) A000005(A007908(n)) ; end; for n from 1 to 50 do printf("%d %d ", n, A110756(n)) ; od ; # R. J. Mathar, Feb 10 2007

CROSSREFS

Cf. A000005, A007908, A110757, A110758, A110759, A110760.

Sequence in context: A021612 A329281 A201587 * A200698 A013661 A209273

Adjacent sequences:  A110753 A110754 A110755 * A110757 A110758 A110759

KEYWORD

nonn,base

AUTHOR

Amarnath Murthy, Aug 11 2005

EXTENSIONS

More terms from R. J. Mathar, Feb 10 2007

More terms from David Wasserman, Dec 22 2008

a(57)-a(65) from Jinyuan Wang, May 23 2020

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 September 23 20:42 EDT 2021. Contains 347617 sequences. (Running on oeis4.)