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A153223 Numbers k such that the string k is found at position k-4 in the decimal digits of Pi.

%I A153223 #10 Jan 30 2022 16:00:40
%S A153223 9,233,1614,9218,27755974,81259258,120526011,238732548,651265325,
%T A153223 783609697
%N A153223 Numbers k such that the string k is found at position k-4 in the decimal digits of Pi.
%e A153223 a(1) = 9 because 9 occurs at offset (9-4) after the decimal in the digits of Pi.
%o A153223 (Python)
%o A153223 from sympy import S
%o A153223 # download https://stuff.mit.edu/afs/sipb/contrib/pi/pi-billion.txt, then
%o A153223 #with open('pi-billion.txt', 'r') as f: pi_digits = f.readline()
%o A153223 pi_digits = str(S.Pi.n(3*10**5+2))[:-2] # alternative to above
%o A153223 pi_digits = pi_digits.replace(".", "")
%o A153223 def afind():
%o A153223     for k in range(5, len(pi_digits)):
%o A153223         sk = str(k)
%o A153223         if sk == pi_digits[k-4:k-4+len(sk)]:
%o A153223             print(k, end=", ")
%o A153223 afind() # _Michael S. Branicky_, Jan 30 2022
%Y A153223 Cf. A057679, A057680, A109513, A109514, A153221, A153224.
%K A153223 base,more,nonn
%O A153223 1,1
%A A153223 _Gil Broussard_, Dec 21 2008
%E A153223 a(5)-a(10) from _Michael S. Branicky_, Jan 30 2022