%I A138339
%S A138339 0,7,4,12
%N A138339 Smallest index in A138343 which starts a plateau of n consecutive integers.
%C A138339 The sequence provides an indication of regions of nearly no
%C A138339 improvements of the sequence of convergents to Pi when measured by
%C A138339 the count of correct digits after rounding. A "plateau" of n consecutive 
               integers
%C A138339 is defined by a(n) = j such that A138343(j) = A138343(j+n-1) and
%C A138339 such that none of the intermediate A138343 with index j+1 up to j+n-2 
               drop below this level.
%e A138339 a(3)=4 because the A138343(4) to A138343(6) are the earliest plateau 
               of length 3.
%e A138339 The fact that there is a local maximum at A138343(5)=9 above the plateau 
               is consistent with the definition.
%Y A138339 Cf. A138335, A138336, A138337, A138338, A138343.
%Y A138339 Sequence in context: A103227 A165415 A069199 this_sequence A107827 A070406 
               A063632
%Y A138339 Adjacent sequences: A138336 A138337 A138338 this_sequence A138340 A138341 
               A138342
%K A138339 nonn,less,base,bref
%O A138339 1,2
%A A138339 Artur Jasinski (grafix(AT)csl.pl), Mar 16 2008
%E A138339 Definition and values adapted to redefined A138343 - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Oct 01 2009