A186943 Number of lunar divisors (in base 10) of the n-th number whose decimal expansion contains only 0's and 1's and begins and ends with a 1 (A099821(n)).

9, 90, 90, 819, 90, 738, 738, 7461, 90, 738, 819, 6570, 738, 6732, 6570, 67968, 90, 738, 738, 6570, 738, 6570, 6732, 59868, 738, 6732, 6570, 59868, 6570, 59868, 59868, 619902, 90, 738, 738, 6570, 819, 6570, 6570, 59058, 738, 6570, 7461, 59058, 6570, 59868, 59058, 539550, 738, 6732, 6570, 59868, 6570, 59058, 59868, 538821, 6570, 59868, 59058, 538902, 59058, 538821, 539550, 5660208, 90, 738, 738, 6570, 738, 6570, 6570

Offset: 1

Author

N. J. A. Sloane, Mar 01 2011

Keywords

• nonn
• base

Comments

Number of lunar divisors of A099821(n), that is, A087029(A099821(n))..

Examples

			1 has 9 divisors: 1,2,3,4,5,6,7,8,9, so a(1)=9. 11 has 90 divisors, 1 through 9 and the numbers 11 through 99 that do not end in 0, so a(2)=90.
		

Links

• N. J. A. Sloane, Table of n, a(n) for n = 1..100
• D. Applegate, M. LeBrun and N. J. A. Sloane, Dismal Arithmetic [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing]
• Index entries for sequences related to dismal (or lunar) arithmetic

Crossrefs

Cf. A087029, A099821.