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 A228089 #19 Oct 12 2013 22:00:58 %S A228089 0,1,2,5,6,8,7,9,10,13,18,21,22,24,23,25,26,30,33,37,38,40,39,41,42, %T A228089 45,50,53,54,56,55,57,58,64,61,66,63,69,70,72,71,73,74,77,82,85,86,88, %U A228089 87,89,90,94,97,101,102,104,103,105,106,109,114,117,118,120,119 %N A228089 Integers k for which a sum k + bitcount(k) cannot be obtained as a sum k2 + bitcount(k2) for any other k2<>k. %C A228089 The values of k's are sorted here according to the magnitude of the sum k + bitcount(k), where bitcount(k) (= A000120) gives the number of 1's in binary representation of nonnegative integer k; a(n) = A228086(A228088(n)). %H A228089 Antti Karttunen, <a href="/A228089/b228089.txt">Table of n, a(n) for n = 1..10000</a> %H A228089 <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a> %F A228089 a(n) = A228086(A228088(n)). %F A228089 A092391(a(n)) = A228088(n). %e A228089 6 is in this sequence because the sum 6+A000120(6)=8 cannot be obtained with any other value of k than k=6. %e A228089 8 is in this sequence because the sum 8+A000120(8)=9 cannot be obtained with any other value of k than k=8. %e A228089 7 is in this sequence because the sum 7+A000120(7)=10 cannot be obtained with any other value of k than k=7. %e A228089 In this sequence 8 becomes before 7 because 8+A000120(8) < 7+A000120(7). %o A228089 (Scheme) (define (A228089 n) (A228086 (A228088 n))) %Y A228089 A228090 gives the same terms sorted into ascending order. %K A228089 nonn %O A228089 1,3 %A A228089 _Antti Karttunen_, Aug 17 2013