A053380 a(n) contains n digits (either '8' or '9') and is divisible by 2^n.

8, 88, 888, 9888, 89888, 989888, 9989888, 89989888, 989989888, 8989989888, 98989989888, 898989989888, 8898989989888, 98898989989888, 998898989989888, 8998898989989888, 98998898989989888, 898998898989989888

Offset

1,1

Links

Ray Chandler, Table of n, a(n) for n = 1..1000

Formula

a(n)=a(n-1)+10^(n-1)*(8+[a(n-1)/2^(n-1) mod 2]) i.e. a(n) ends with a(n-1); if (n-1)-th term is divisible by 2^n then n-th term begins with an 8, if not then n-th term begins with a 9.

Crossrefs

Cf. A023415, A050621, A050622, A035014.

Sequence in context: A053379 A002282 A112907 * A250166 A247738 A115864

Adjacent sequences: A053377 A053378 A053379 * A053381 A053382 A053383

Keyword

base,nonn

Author

Henry Bottomley, Mar 06 2000

Status

approved