A292145 - OEIS

%I #12 Oct 19 2017 08:34:17

%S 1,2,4,3,9,8,5,6,16,12,7,18,25,10,11,20,27,36,32,13,24,14,15,28,49,17,

%T 50,48,19,45,64,21,22,40,23,54,72,44,81,26,75,63,29,52,30,100,31,80,

%U 56,98,33,60,34,35,121,108,37,96,38,68,39,90,128,41,42,144

%N A permutation of the natural numbers: A292144(A013929(n)).

%H Peter Kagey, <a href="/A292145/b292145.txt">Table of n, a(n) for n = 1..10000</a>

%o (PARI) a292144(n) = forstep (k=n-1, 1, -1, if (issquare(k*n), return (k))); return (0);

%o lista(nn) = apply(x->a292144(x), select(x->(! issquarefree(x)), vector(nn, kk, kk))); \\ _Michel Marcus_, Sep 10 2017

%Y Cf. A013929, A292144.

%K nonn

%O 1,2

%A _Peter Kagey_, Sep 09 2017