A337927 a(n) = n / GCD (n, reverse of n).

1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 1, 4, 13, 14, 5, 16, 17, 2, 19, 10, 7, 1, 23, 4, 25, 13, 3, 14, 29, 10, 31, 32, 1, 34, 35, 4, 37, 38, 13, 10, 41, 7, 43, 1, 5, 23, 47, 4, 49, 10, 17, 52, 53, 6, 1, 56, 19, 58, 59, 10, 61, 31, 7, 32, 65, 1, 67, 34, 23, 10, 71, 8, 73, 74, 25, 76, 1, 26, 79

Offset: 1

Author

Ctibor O. Zizka, Oct 05 2020

Keywords

• base
• easy
• nonn
• look

Comments

a(n)=n for n in A226778. - Robert Israel, Oct 09 2020

Examples

			a(12) = 4 since 12 / gcd(12,21) = 4. a(101) = 101 / gcd(101,101) = 1.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000027, A002113, A004086, A055483, A226778.

Programs

Maple

rev:= proc(n) local L,k;
  L:= convert(n,base,10);
  add(L[-k]*10^(k-1),k=1..nops(L))
end proc:
f:= n -> n/igcd(n,rev(n)):
map(f, [$1..100]); # Robert Israel, Oct 09 2020

Mathematica

Table[n/GCD[n, IntegerReverse[n]], {n, 1, 100}] (* Amiram Eldar, Oct 05 2020 *)

PARI

a(n) = n/gcd(n, fromdigits(Vecrev(digits(n)))); \\ Michel Marcus, Oct 06 2020

Formula

a(n) = n / gcd(n, A004086(n)).

a(n) = n / A055483(n).

a(n) = A000027(n) / A055483(n).