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A258158
Indices of the start of 9 successive distinct digits in the decimal expansion of Pi.
2
61, 62, 63, 2007, 2008, 2187, 2188, 2402, 2814, 3312, 3313, 5013, 5471, 5472, 5473, 6856, 7114, 7116, 7117, 7548, 7633, 7634, 7635, 7904, 8080, 8158, 8245, 8246, 8667, 8668, 8669, 8670, 10100, 10131, 10207, 10244, 10552, 11090, 11548, 11621, 11681, 12298
OFFSET
1,1
COMMENTS
It is natural to conjecture that a(n) ~ 156250n/567. - Charles R Greathouse IV, May 22 2015
LINKS
EXAMPLE
63 is in the sequence because the 9 digits starting at the 63rd digit of Pi are 9, 2, 3, 0, 7, 8, 1, 6, 4.
MATHEMATICA
pan[s_, n_]:=Select[Range[Length@s-n+1], Length@ Union@ Take[s, {#, #+n-1}]==n&]; pan[RealDigits[Pi, 10, 10^5][[1]], 9] (* Giovanni Resta, May 22 2015 *)
PROG
(PARI)
default(realprecision, 50080);
infix(v, a, b) = {my(i, s=[]); for(i=a, b, s=concat(s, v[i])); s}
panpi(m) = {
L=List(); p=Pi; for(n=1, 50000, d=floor(p); p=(p-d)*10; listput(L, d)); v=Vec(L);
s=[]; for(k=1, #v-m+1, in=infix(v, k, k+m-1); if(#in==#vecsort(in, , 8), s=concat(s, k))); s
}
panpi(9)
CROSSREFS
Sequence in context: A276471 A122568 A075028 * A364715 A042859 A258157
KEYWORD
nonn,base
AUTHOR
Colin Barker, May 22 2015
STATUS
approved