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.
%I A257807 #12 May 13 2015 15:44:12 %S A257807 0,1,1,1,2,2,2,3,3,4,4,4,5,5,5,5,5,6,7,7,7,8,8,9,10,11,11,12,12,12,13, %T A257807 13,13,13,14,15,15,15,16,16,16,17,18,18,18,18,18,18,18,19,19,19,20,21, %U A257807 22,23,23,24,24,24,25,25,25,25,26,27,27,27,28,28,29,29,29,30,31,32,33,34,34,34,34,35,36,37,37,37,37,37,37,37,38 %N A257807 a(n) = number of odd numbers in range 0 .. n of A233271, the infinite trunk of inverted binary beanstalk. %C A257807 a(0) = 0; and for n >= 1: a(n) = the largest number k such that A257803(k) <= n. %H A257807 Antti Karttunen, <a href="/A257807/b257807.txt">Table of n, a(n) for n = 0..16405</a> %F A257807 a(0) = 0; for n >= 1, a(n) = A257800(n) + a(n-1). %F A257807 Other identities: %F A257807 For all n >= 0, a(n) = A257808(n) - A257806(n). %F A257807 For all n >= 1, a(A257803(n)) = n. [This sequence works as a left inverse of injection A257803.] %o A257807 (Scheme, with memoization-macro definec) %o A257807 (definec (A257807 n) (if (zero? n) n (+ (A257800 n) (A257807 (- n 1))))) %Y A257807 Partial sums of A257800. %Y A257807 Cf. A233271, A257803, A257806, A257808. %K A257807 nonn %O A257807 0,5 %A A257807 _Antti Karttunen_, May 12 2015