cp's OEIS Frontend

A349228 Products of three consecutive terms of A349227: a(n) = A349227(n) * A349227(n+1) * A349227(n+2).

%I A349228 #11 Nov 18 2021 02:41:25
%S A349228 1,2,4,8,12,6,3,5,10,20,16,24,36,9,15,25,50,30,18,27,45,60,40,32,48,
%T A349228 72,54,63,21,7,11,22,44,28,14,35,55,110,66,42,84,56,64,80,120,75,90,
%U A349228 150,180,210,126,105,135,225,270,240,96,112,70,140,100,160,200
%N A349228 Products of three consecutive terms of A349227: a(n) = A349227(n) * A349227(n+1) * A349227(n+2).
%C A349228 All terms are distinct.
%C A349228 Is this sequence a permutation of the natural numbers?
%H A349228 Rémy Sigrist, <a href="/A349228/b349228.txt">Table of n, a(n) for n = 1..10000</a>
%e A349228 a(5) = A349227(5) * A349227(6) * A349227(7) = 2 * 2 * 3 = 12.
%o A349228 (PARI) s=0; pp=p=1; for (n=1, 63, for (v=1, oo, if (!bittest(s, q=pp*p*v), print1 (q", "); s+=2^q; pp=p; p=v; break)))
%o A349228 (Python)
%o A349228 def aupton(terms):
%o A349228     A349227lst, plst, pset = [1, 1], [], set()
%o A349228     for n in range(terms):
%o A349228         p = p2 = A349227lst[-1]*A349227lst[-2]
%o A349228         while p in pset: p += p2
%o A349228         A349227lst.append(p//p2); plst.append(p); pset.add(p)
%o A349228     return plst
%o A349228 print(aupton(63)) # _Michael S. Branicky_, Nov 12 2021
%Y A349228 Cf. A088177, A349227.
%K A349228 nonn
%O A349228 1,2
%A A349228 _Rémy Sigrist_, Nov 11 2021