%I #34 Jul 29 2024 05:04:35
%S 1,3,37,40,49,68,94,95,103,110,138,148,153,154,155,163,168,174,175,
%T 198,206,220,238,243,246,250,269,281,295,297,314,319,324,342,344,362,
%U 363,381,385,390,393,395,396,417,424,427,428,432,437,438,442,445,446
%N Positions of the digit '1' in the decimal expansion of Pi.
%C From _M. F. Hasler_, Jul 28 2024: (Start)
%C "Positions" are indices n of digits d(n) such that Pi = Sum_{n >= 0} d(n)/10^n; see A053745 for the variant where the initial digit 3 is at position 1.
%C The first few primes in this sequence are 3, 37, 103, 163, 269, 281, 499, 541, 547, 587, 607, 709, 797, 859, 887, 971, 983, 997, ... (End)
%H Robert Israel, <a href="/A037000/b037000.txt">Table of n, a(n) for n = 1..10137</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PiDigits.html">Pi Digits</a>
%F Conjecturally, a(n) ~ 10n.
%p P:= convert(evalf[100000](Pi),string)[3..-1]:
%p select(t -> P[t]="1",[$1..length(P)-1]); # _Robert Israel_, Dec 22 2013
%t Flatten @ Position[ RealDigits[Pi - 3, 10, 500][[1]], 1] (* _Robert G. Wilson v_, Mar 07 2011 *)
%o (PARI) A037000_upto(N=500, d=1)={localprec(N+20); [i-1|i<-[1..#N=digits(Pi\10^-N)], N[i]==d]} \\ _M. F. Hasler_, Jul 28 2024
%Y Cf. A000796 (decimals of Pi), A037001 - A037008 and A036974 (positions of other digits), A053745 (variant with all values increased by 1).
%K base,nonn
%O 1,2
%A Nicolau C. Saldanha (nicolau(AT)mat.puc-rio.br)