A190151 A190149 converted to base 10 and halved.

9, 17, 19, 25, 33, 34, 35, 37, 39, 41, 49, 51, 57, 65, 66, 67, 69, 70, 71, 73, 75, 77, 79, 81, 83, 89, 97, 98, 99, 101, 103, 105, 113, 115, 121, 129, 130, 131, 132, 133, 134, 135, 137, 138, 139, 141, 142, 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 162, 163, 165, 167, 169, 177, 179, 185, 193, 194, 195, 197, 198, 199, 201, 203, 205, 207, 209, 211

Offset: 1

Author

N. J. A. Sloane, May 05 2011

Keywords

• nonn
• base

Comments

Take the even numbers n such that in base 2 lunar arithmetic, the sum of the divisors of n is not of the form 2^k-1, and divide them (in ordinary arithmetic) by 2 (cf. A190149, A190150)

Links

• 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]
• D. Applegate, M. LeBrun, N. J. A. Sloane, Dismal Arithmetic, J. Int. Seq. 14 (2011) # 11.9.8.
• Index entries for sequences related to dismal (or lunar) arithmetic

Crossrefs

Cf. A188548, A190149, A190150.