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.

A274089 Numbers repeated except that powers of 2 only appear once.

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%I A274089 #17 Sep 05 2024 17:38:07
%S A274089 1,2,3,3,4,5,5,6,6,7,7,8,9,9,10,10,11,11,12,12,13,13,14,14,15,15,16,
%T A274089 17,17,18,18,19,19,20,20,21,21,22,22,23,23,24,24,25,25,26,26,27,27,28,
%U A274089 28,29,29,30,30,31,31,32,33,33,34,34,35,35,36,36,37,37,38,38,39,39,40,40
%N A274089 Numbers repeated except that powers of 2 only appear once.
%F A274089 a(n) = floor(A057716(n) / 2). - _Kevin Ryde_, Apr 28 2024
%o A274089 (PARI) a(n) = n++; my(k=logint(n,2)); n+=k; (n + bittest(n,k+1)) >> 1; \\ _Kevin Ryde_, Apr 28 2024
%o A274089 (Python)
%o A274089 def A274089(n): return n+(k:=n.bit_length())+bool(n+k&(1<<k))>>1 # _Chai Wah Wu_, Sep 05 2024
%Y A274089 Cf. A057716.
%Y A274089 Conjectured to be (essentially) the first differences of A002960.
%K A274089 nonn,easy
%O A274089 1,2
%A A274089 _N. J. A. Sloane_, Jun 10 2016