A342345 - OEIS

A342345

a(1) = 3, a(n) = smallest palindromic nontrivial multiple of a(n-1) containing all decimal digits of a(n-1).

%I #11 Mar 10 2021 16:32:21

%S 3,33,363,36663,6306036,63066666036,6304963866683694036,

%T 6304963866689998999866683694036

%N a(1) = 3, a(n) = smallest palindromic nontrivial multiple of a(n-1) containing all decimal digits of a(n-1).

%C Differs from A082778 at a(5). a(n) <= (10^A055642(a(n-1))+1)*a(n-1). If a(n-1) > 10 and the last digit of a(n-1) <= 4, then a(n) <= (10^(A055642(a(n-1))-1)+1)*a(n-1).

%e a(4) = 3663 is a palindromic multiple of a(3) = 363 and contains 2 '3' and 1 '6', all the digits of a(3).

%Y Cf. A055642, A082778.

%K nonn,base,more

%O 1,1

%A _Chai Wah Wu_, Mar 08 2021

%E a(8) from _Martin Ehrenstein_, Mar 10 2021