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%I #12 Mar 27 2020 06:42:29
%S 20,22,18,18,19,19,19,22,22,22,20,19,21,21,21,22,25,22,24,23,24,24,23,
%T 23,25,24,26,25,25,26,27,27,26,29,29,26,27,26,26,25,24,21,21,20,19,20,
%U 20,20,20,20,20,20,19,21,24,23,23,23,23,22,21,23,23,25,26,26,25,26,26
%N In the decimal expansion of Pi, lengths of subsequences with sum = 100.
%C Average length is about 100/4.5=22.22 because average decimal digit is about 4.5.
%F a(n) = A109211(n) - A109210(n) + 1.
%o (PARI) default(realprecision, 101000); v=digits(floor(Pi*10^10^5));
%o lista(nn) = {my(x=21, s=103); for(k=2, nn, s-=v[k-1]; if(s==100, print1(x-k+1, ", "), while(s<100, s+=v[x++]); if(s==100, print1(x-k+1, ", ")))); } \\ _Jinyuan Wang_, Mar 22 2020
%Y Cf. A000796, A109210, A109211.
%K base,nonn
%O 1,1
%A _Zak Seidov_, Jun 22 2005
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