A265690 Cardinality of shortest addition chain for n.

1, 2, 3, 3, 4, 4, 5, 4, 5, 5, 6, 5, 6, 6, 6, 5, 6, 6, 7, 6, 7, 7, 7, 6, 7, 7, 7, 7, 8, 7, 8, 6, 7, 7, 8, 7, 8, 8, 8, 7, 8, 8, 8, 8, 8, 8, 9, 7, 8, 8, 8, 8, 9, 8, 9, 8, 9, 9, 9, 8, 9, 9, 9, 7, 8, 8, 9, 8, 9, 9, 10, 8, 9, 9, 9, 9, 9, 9, 10, 8, 9, 9, 9, 9, 9, 9, 10, 9, 10, 9, 10, 9, 10, 10, 10, 8, 9, 9, 9, 9

Offset

1,2

Comments

The cardinality of an addition chain is the number of terms in it, including the initial 1; hence it is one more than the length of the chain (A003313).

Links

Table of n, a(n) for n=1..100.

Wikipedia, Addition chain

Formula

a(n) = A003313(n) + 1.

Crossrefs

Cf. A003313 (much more information and links), A265691, A265692.

Sequence in context: A325134 A218007 A060607 * A061339 A073933 A056792

Adjacent sequences: A265687 A265688 A265689 * A265691 A265692 A265693

Keyword

nonn

Author

Franklin T. Adams-Watters, Dec 13 2015

Status

approved