A277827 Digits that appear twice consecutively in the decimal expansion of Pi, in order of appearance.

3, 8, 9, 4, 9, 1, 6, 4, 5, 2, 1, 1, 1, 5, 5, 4, 2, 4, 8, 6, 3, 4, 3, 6, 6, 3, 0, 6, 5, 8, 8, 0, 1, 3, 8, 6, 1, 3, 1, 1, 1, 4, 9, 8, 2, 1, 3, 3, 4, 6, 2, 7, 6, 0, 0, 7, 7, 7, 4, 2, 2, 9, 1, 4, 7, 7, 9, 1, 9, 9, 9, 9, 9, 9, 4, 5, 2, 3, 4, 1, 8, 0, 0, 8, 3, 7, 6, 5, 1, 8, 7, 7, 2, 6, 0, 6, 1, 1, 8, 3

Offset

1,1

Comments

A digit d of Pi is in this sequence iff A000796(i) = A000796(i+1), where i is the index of d in A000796. - Felix Fröhlich, Nov 01 2016

Links

Table of n, a(n) for n=1..100.

Formula

a(n) = A000796(A049514(n)).

Example

Pi=3.14159265358979323846264(33)83279502(88)41971693(99)3751058209749(44)592307816406286208(99)8628034825342(11)70679...
Therefore, this sequence starts 3, 8, 9, 4, 9, 1.

Prog

(PARI) pidigit(n) = floor(Pi*10^n) - 10*floor(Pi*10^(n-1))
terms(n) = my(k=1, i=0); while(1, if(pidigit(k)==pidigit(k+1), print1(pidigit(k), ", "); i++); if(i==n, break); k++)
/* Print initial 100 terms as follows */
terms(100) \\ Felix Fröhlich, Nov 01 2016

Crossrefs

Cf. A000796, A049514.

Sequence in context: A177272 A010630 A197811 * A011276 A021882 A079591

Adjacent sequences: A277824 A277825 A277826 * A277828 A277829 A277830

Keyword

nonn,base

Author

Bobby Jacobs, Nov 01 2016

Status

approved