a(4)=a(5)=a(6) = 9 because there are (exactly) six consecutive 9's occurring with starting index A049522(4)=A049522(5)=A049522(6) = 763 and there are no runs of 4, 5, 6, or more consecutive equal digits having a smaller starting index.
The first occurrence of a run of at least seven consecutive equal digits occurs at starting index A049522(7) = 710101. The run consists of exactly seven 3's so a(7) = 3 [=A084144(7)] and also A049523(7) = 710101.
CROSSREFS
Cf. A049522 (starting index), A084144 (consecutively exactly n times), A049523 (starting index for A084144 runs).
