cp's OEIS Frontend

A143051 Smallest number not occurring earlier and smaller than the largest square so far, the next square if no such number exists.

%I A143051 #8 Sep 22 2015 18:52:13
%S A143051 0,1,4,2,3,9,5,6,7,8,16,10,11,12,13,14,15,25,17,18,19,20,21,22,23,24,
%T A143051 36,26,27,28,29,30,31,32,33,34,35,49,37,38,39,40,41,42,43,44,45,46,47,
%U A143051 48,64,50,51,52,53,54,55,56,57,58,59,60,61,62,63,81,65,66,67,68,69,70,71
%N A143051 Smallest number not occurring earlier and smaller than the largest square so far, the next square if no such number exists.
%C A143051 Permutation of the natural numbers, inverse: A143052;
%C A143051 A143053(n) = a(a(n));
%C A143051 a(A000290(n)) = A005563(n-1);
%C A143051 a(A002522(n)) = A000290(n+1);
%C A143051 for n>1: GCD(a(n^2),a(n^2+1)) = A050873(A000290(n),A002522(n)) =
%C A143051 A022998(n+1).
%H A143051 Peter Kagey, <a href="/A143051/b143051.txt">Table of n, a(n) for n = 0..10000</a>
%H A143051 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F A143051 a(n) = if n=0 then 0 else if n=1+k^2 then n+2*k else n-1.
%K A143051 nonn
%O A143051 0,3
%A A143051 _Reinhard Zumkeller_, Jul 20 2008