A190820 -id:A190820 - cp's OEIS frontend

A191342 2^(n-1)-A190820(n).

Original entry on oeis.org

0, 0, 0, 1, 3, 9, 23, 59, 145, 346, 787, 1770, 3899, 8482, 18337

Offset: 2

N. J. A. Sloane, Jun 01 2011

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

Cf, A190820.

A120411 If A is a set of integers, the (2-fold) sumset consists of all the numbers which can be written as the sum of two (not necessarily distinct) elements in A. a(n) is the number of subsets of [1,2n] which are sumsets for some set of positive integers.

Original entry on oeis.org

1, 3, 7, 15, 30, 59, 114, 219, 416, 783, 1461, 2722, 5048, 9341, 17243, 31674, 58037, 105936, 192522, 348832

Offset: 1

David S. Newman, Jul 05 2006

The relation a(n+1)-a(n) = A190820(n) seems to hold. - Giovanni Resta, Jan 15 2013

			a(5)=30 because two of the 31 (nonempty) subsets of [1,5], namely {1,2,4,5} and {1,2,3,4,5} have the sumset {2,3,4,5,6,7,8,9,10} and no two other subsets of [1,5] have the same sumset.

a(14)-a(20) from Carl Najafi, Jan 15 2013

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A191342 2^(n-1)-A190820(n).

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A120411 If A is a set of integers, the (2-fold) sumset consists of all the numbers which can be written as the sum of two (not necessarily distinct) elements in A. a(n) is the number of subsets of [1,2n] which are sumsets for some set of positive integers.

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