A265500 Balance scale sequence.

1, 2, 7, 21, 52, 167, 501, 1503, 4509, 13527, 40581

Offset

1,2

Comments

Every natural number up to sum(a[1], a[i]) can be written as adding or subtracting unique entries up to a(i).

Links

Table of n, a(n) for n=1..11.

The Ben Paul Thurston Blog, Balance scale series

Formula

a(i+1)= 1+2*sum(a[1], a[i]) (proved).

Example

17 = 21-7+1+2, 18=21-1-2, 19=17+2.

Crossrefs

Sequence in context: A352017 A265316 A079034 * A212338 A246861 A305601

Adjacent sequences: A265497 A265498 A265499 * A265501 A265502 A265503

Keyword

nonn,more

Author

Ben Paul Thurston, Dec 09 2015

Status

approved