A038805 Difference between last prime < 10^n and 10^n is a record high.

1, 4, 9, 21, 24, 34, 56, 66, 92, 100, 112, 117, 135, 180, 260, 349, 387, 393, 411, 574, 617, 787, 1209

Offset

1,2

Links

Table of n, a(n) for n=1..23.

Example

For a(19)=411, the difference is 4433 and no other n <= 540 exceeds that difference.

Mathematica

PrevPrim[n_] := Block[{k = n - 1}, While[ !PrimeQ[k], k-- ]; k]; d = 0; k = 1; Do[ While[f = 10^k - PrevPrim[10^k]; d >= f, k++ ]; d = f; Print[k], {n, 1, 50}]

Crossrefs

Cf. A033874.

Sequence in context: A147971 A197869 A276319 * A192162 A251545 A228642

Adjacent sequences: A038802 A038803 A038804 * A038806 A038807 A038808

Keyword

base,nonn

Author

Jeff Burch

Extensions

Edited and extended by Robert G. Wilson v, Jun 18 2002

a(23) from Robert G. Wilson v, Jan 10 2007

Status

approved