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.

A361676 a(n) is the greatest k such that n appears in the k-th row of triangle A361644.

This page as a plain text file.
%I A361676 #12 Mar 22 2023 12:48:00
%S A361676 0,1,2,3,5,5,6,7,11,10,10,11,13,13,14,15,23,22,21,21,21,21,22,23,27,
%T A361676 26,26,27,29,29,30,31,47,46,45,45,43,42,42,43,43,42,42,43,45,45,46,47,
%U A361676 55,54,53,53,53,53,54,55,59,58,58,59,61,61,62,63,95,94,93
%N A361676 a(n) is the greatest k such that n appears in the k-th row of triangle A361644.
%C A361676 All terms belong to A003754.
%C A361676 To compute a(n): consider the run lengths in the binary expansion of n (i.e. the n-th row of A101211) and replace from left to right each value v > 1 at even index with (1, v-1); at the end, there remain the run lengths in the binary expansion of a(n).
%C A361676 See A361645 for the least k's.
%H A361676 Rémy Sigrist, <a href="/A361676/b361676.txt">Table of n, a(n) for n = 0..8191</a>
%H A361676 Rémy Sigrist, <a href="/A361676/a361676.gp.txt">PARI program</a>
%H A361676 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%F A361676 a(n) >= n with equality iff n belongs to A003754.
%F A361676 a(n) >= A361645(n) with equality iff n belongs to A000975.
%e A361676 The first terms, in decimal and in binary, are:
%e A361676   n   a(n)  bin(n)  bin(a(n))
%e A361676   --  ----  ------  ---------
%e A361676    0     0       0          0
%e A361676    1     1       1          1
%e A361676    2     2      10         10
%e A361676    3     3      11         11
%e A361676    4     5     100        101
%e A361676    5     5     101        101
%e A361676    6     6     110        110
%e A361676    7     7     111        111
%e A361676    8    11    1000       1011
%e A361676    9    10    1001       1010
%e A361676   10    10    1010       1010
%e A361676   11    11    1011       1011
%e A361676   12    13    1100       1101
%e A361676   13    13    1101       1101
%e A361676   14    14    1110       1110
%e A361676   15    15    1111       1111
%o A361676 (PARI) See Links section.
%Y A361676 Cf. A000975, A003754, A101211, A361644, A361645.
%K A361676 nonn,base
%O A361676 0,3
%A A361676 _Rémy Sigrist_, Mar 20 2023