1,1

a(n) is the unique positive integer less than 10^n such that a(n) + 2^(n-1) + 1 is divisible by 2^n and a(n) - 1 is divisible by 5^n.

Eric M. Schmidt, Table of n, a(n) for n = 1..1000

Eric Weisstein's World of Mathematics, Trimorphic Number

Index entries for sequences related to automorphic numbers

a(n) = (A224474(n) + 10^n/2) mod 10^n.

(Sage) def A224476(n) : return crt(2^(n-1)-1, 1, 2^n, 5^n)

Cf. A033819. Converges to the 10-adic number A063006. The other trimorphic numbers ending in 1 are included in A199685 and A224474.

Sequence in context: A009330 A266302 A183284 * A123147 A119831 A224842

Adjacent sequences: A224473 A224474 A224475 * A224477 A224478 A224479

nonn,base

Eric M. Schmidt, Apr 07 2013

approved