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.

A242313 Numbers belonging to a geometric sequence whose ratio is 2 and whose first term ends in 1.

This page as a plain text file.
%I A242313 #21 Jun 09 2022 21:50:42
%S A242313 1,2,4,8,11,16,21,22,31,32,41,42,44,51,61,62,64,71,81,82,84,88,91,101,
%T A242313 102,111,121,122,124,128,131,141,142,151,161,162,164,168,171,176,181,
%U A242313 182,191,201,202,204,211,221,222,231,241,242,244,248,251,256,261
%N A242313 Numbers belonging to a geometric sequence whose ratio is 2 and whose first term ends in 1.
%C A242313 Numbers such that A099551(n) = 1.
%C A242313 Numbers of the form 2^m * (10n + 1). - _Charles R Greathouse IV_, May 14 2014
%F A242313 a(n) = 5n + O(log n). - _Charles R Greathouse IV_, May 14 2014
%e A242313 176 is in the sequence because it belongs to 11, 22, 44, 88, 176, with first term 11.
%e A242313 96, which belongs to 3, 6, 12, 24, 48, 96 with first term 3, is not a term.
%o A242313 (PARI) isok(n) = ((n/2^valuation(n, 2)) % 10) == 1; \\ _Michel Marcus_, May 14 2014
%Y A242313 Cf. A099551.
%K A242313 nonn,base,easy
%O A242313 1,2
%A A242313 _J. Lowell_, May 10 2014
%E A242313 More terms from _Michel Marcus_, May 14 2014