OFFSET
0,1
COMMENTS
Digits 3,1,4,... are indexed 1,2,3,...
See A049514 for the variant "at least 2", which differs from a(11) on. - M. F. Hasler, Oct 18 2019
EXAMPLE
From M. F. Hasler, Oct 18 2019: (Start)
The integer part of Pi*10^22 ends in 33, i.e., at position 22 starts the (first) string of two repeated digits 3, therefore a(1) = 22.
At position 154 starts a string of three '1's, so sequence A049514 lists both, 154 and 155, but this sequence lists none of these. (End)
MATHEMATICA
Flatten[Position[Partition[RealDigits[Pi, 10, 1000][[1]], 4, 1], _?(#[[1]] != #[[2]] && #[[2]]==#[[3]]&&#[[3]]!=#[[4]]&), 1, Heads->False]]+1 (* Harvey P. Dale, Jul 08 2017 *)
PROG
(PARI) A049518_upto(N=999)={default(realprecision, N); my(p=digits(Pi\10^-N)); select(i->p[i]==p[i+1] && p[i]!=p[i-1] && p[i]!=p[i+2], [9..N-2])} \\ M. F. Hasler, Oct 18 2019
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved