A138339 Smallest index in A138343 which starts a plateau of n consecutive integers.

0, 7, 4, 12

Offset

1,2

Comments

The sequence provides an indication of regions of nearly no improvements of the sequence of convergents to Pi when measured by the count of correct digits after rounding. A "plateau" of n consecutive integers is defined by a(n) = j such that A138343(j) = A138343(j+n-1) and such that none of the intermediate A138343 with index j+1 up to j+n-2 drop below this level.

Links

Table of n, a(n) for n=1..4.

Example

a(3)=4 because the A138343(4) to A138343(6) are the earliest plateau of length 3.
The fact that there is a local maximum at A138343(5)=9 above the plateau is consistent with the definition.

Crossrefs

Cf. A138335, A138336, A138337, A138343.

Sequence in context: A165415 A069199 A359014 * A107827 A070406 A323997

Adjacent sequences: A138336 A138337 A138338 * A138340 A138341 A138342

Keyword

nonn,less,base,bref

Author

Artur Jasinski, Mar 16 2008

Extensions

Definition and values adapted to redefined A138343 - R. J. Mathar, Oct 01 2009

Status

approved