A265404 a(n) = number of Spironacci numbers (A078510) needed to sum to n using the greedy algorithm.

0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2

Offset

0,18

Comments

a(0) = 0, because no numbers are needed to form an empty sum, which is zero.

First 2 occurs as a(17), first 3 at a(234), first 4 at a(3266).

Links

Antti Karttunen, Table of n, a(n) for n = 0..10132

Example

For n=17, the largest Spironacci number <= 17 is 16 (= A078510(22)). 17 - 16 = 1, which is A078510(1), thus 17 = A078510(22) + A078510(1), requiring only two such numbers for its sum, thus a(17) = 2.
For n=234, the largest Spironacci number <= 234 is 217 (= A078510(45)). 234-217 = 17 (whose decomposition is shown above), so 234 = A078510(45) + A078510(22) + A078510(1), thus a(234) = 3.

Crossrefs

Cf. A078510 (from its term a(7) onward gives also the positions of ones here).

Cf. also A007895, A053610, A265743, A265744, A265745.

Sequence in context: A113189 A143098 A225515 * A274353 A183028 A114284

Adjacent sequences: A265401 A265402 A265403 * A265405 A265406 A265407

Keyword

nonn

Author

Antti Karttunen, Dec 16 2015

Status

approved