cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

This page as a plain text file.
%I A265404 #21 Dec 18 2015 11:25:03
%S A265404 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,
%T A265404 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,
%U A265404 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
%N A265404 a(n) = number of Spironacci numbers (A078510) needed to sum to n using the greedy algorithm.
%C A265404 a(0) = 0, because no numbers are needed to form an empty sum, which is zero.
%C A265404 First 2 occurs as a(17), first 3 at a(234), first 4 at a(3266).
%H A265404 Antti Karttunen, <a href="/A265404/b265404.txt">Table of n, a(n) for n = 0..10132</a>
%e A265404 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.
%e A265404 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.
%Y A265404 Cf. A078510 (from its term a(7) onward gives also the positions of ones here).
%Y A265404 Cf. also A007895, A053610, A265743, A265744, A265745.
%K A265404 nonn
%O A265404 0,18
%A A265404 _Antti Karttunen_, Dec 16 2015