cp's OEIS Frontend

A188649 Least common multiple of reversals of divisors of n in decimal representation.

%I A188649 #23 Aug 15 2022 05:23:23
%S A188649 1,2,3,4,5,6,7,8,9,10,11,84,31,574,255,488,71,162,91,20,84,22,32,168,
%T A188649 260,62,72,1148,92,510,13,11224,33,6106,1855,2268,73,15106,93,40,14,
%U A188649 6888,34,44,4590,64,74,10248,658,260,1065,3100,35,3240,55,149240,6825,7820,95,7140,16,26,252,11224,8680,66,76,12212,96,152110,17,4536,37,6862,251940,2024204,77
%N A188649 Least common multiple of reversals of divisors of n in decimal representation.
%H A188649 Reinhard Zumkeller, <a href="/A188649/b188649.txt">Table of n, a(n) for n = 1..10000</a>
%H A188649 <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a>
%F A188649 a(A000040(n)) = A004087(n);
%F A188649 a(A002385(n)) = A002385(n), see A188650 for all fixed points.
%e A188649 Divisors(42) = {1,2,3,6,7,14,21,42}, therefore a(42) = lcm(1,2,3,6,7,41,12,24) = 6888.
%o A188649 (Haskell)
%o A188649 a188649 n = foldl lcm 1 $ map a004086 $ filter ((== 0) . mod n) [1..n]
%o A188649 (PARI) a(n) = lcm(apply(x->fromdigits(Vecrev(digits(x))), divisors(n))); \\ _Michel Marcus_, Mar 13 2018
%o A188649 (Python)
%o A188649 from math import lcm
%o A188649 from sympy import divisors
%o A188649 def a(n): return lcm(*(int(str(d)[::-1]) for d in divisors(n)))
%o A188649 print([a(n) for n in range(1, 78)]) # _Michael S. Branicky_, Aug 14 2022
%Y A188649 Cf. A003990 (LCM), A027750 (divisors), A004086 (reversal), A188650.
%Y A188649 Cf. A000040, A004087, A002385.
%K A188649 nonn,base
%O A188649 1,2
%A A188649 _Reinhard Zumkeller_, Apr 11 2011