A053378 a(n) contains n digits (either '5' or '8') and is divisible by 2^n.

8, 88, 888, 5888, 85888, 885888, 8885888, 58885888, 558885888, 8558885888, 58558885888, 858558885888, 5858558885888, 85858558885888, 585858558885888, 5585858558885888, 55585858558885888, 855585858558885888

Offset

1,1

Links

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

Formula

a(n)=a(n-1)+10^(n-1)*(8-3*[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 5.

Crossrefs

Cf. A023413, A050621, A050622, A035014.

Sequence in context: A368919 A053376 A053377 * A062185 A053379 A002282

Adjacent sequences: A053375 A053376 A053377 * A053379 A053380 A053381

Keyword

base,nonn

Author

Henry Bottomley, Mar 06 2000

Status

approved