OFFSET
1,2
LINKS
Sean A. Irvine, Table of n, a(n) for n = 1..84
EXAMPLE
The number of divisors of 13 is 2, hence a(2) = 2.
The number of divisors of 135 is 8, hence a(3) = 8.
The number of divisors of 1357 is 4, hence a(4) = 4.
MAPLE
R:= 1: x:= 1:
for n from 2 to 49 do
x:= x*10^(1+ilog10(2*n-1)) + 2*n - 1;
R:= R, numtheory:-tau(x);
od:
R; # Robert Israel, Mar 02 2023
MATHEMATICA
ParallelTable[Divisors[FromDigits[Join@@IntegerDigits/@Table[1+2*k, {k, 0, n}]]]//Length, {n, 0, 48}] (* J.W.L. (Jan) Eerland, Mar 02 2023 *)
CROSSREFS
KEYWORD
base,nonn,more
AUTHOR
Parthasarathy Nambi, Apr 30 2005, Jul 01 2005
EXTENSIONS
Edited by N. J. A. Sloane, Aug 23 2008 at the suggestion of R. J. Mathar
a(18)-a(50) from J.W.L. (Jan) Eerland, Mar 02 2023
a(51)-a(58) from Jon E. Schoenfield, Mar 03 2023
Offset corrected by Sean A. Irvine, Mar 24 2023
STATUS
approved