OFFSET
1,2
LINKS
Tyler Busby, Table of n, a(n) for n = 1..117
FORMULA
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
MATHEMATICA
Table[DivisorSigma[0, FromDigits[Flatten[IntegerDigits/@Range[n]]]], {n, 60}] (* Harvey P. Dale, Apr 01 2024 *)
CROSSREFS
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