OFFSET
1,2
LINKS
Max Alekseyev, Table of n, a(n) for n = 1..158
FORMULA
EXAMPLE
a(3) = tau(333) = 6.
MATHEMATICA
f[n_] := Sum[n*10^(i * Length[IntegerDigits[n]]), {i, 0, n - 1}]; Do[Print[DivisorSigma[0, f[n]]], {n, 100}] (* Ryan Propper, Jul 21 2006 *)
Table[DivisorSigma[0, FromDigits[Flatten[IntegerDigits/@PadRight[{}, n, n]]]], {n, 50}] (* Harvey P. Dale, Apr 10 2023 *)
PROG
(PARI) a(n) = numdiv(eval(concat(apply(x->Str(x), vector(n, k, n))))); \\ Michel Marcus, Feb 12 2023
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Aug 11 2005
EXTENSIONS
Corrected and extended by Ryan Propper, Jul 21 2006
STATUS
approved