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A153227
Numbers k such that the string k is found at position 2k in the decimal digits of Pi.
1
5, 95, 171, 529, 1913, 2753, 60597, 831092, 9552919
OFFSET
1,1
EXAMPLE
a(2) = 95 because 95 occurs at offset 190 (2*95) after the decimal in the digits of Pi.
PROG
(Python)
from sympy import S
# download https://stuff.mit.edu/afs/sipb/contrib/pi/pi-billion.txt, then
#with open('pi-billion.txt', 'r') as f: pi_digits = f.readline()
pi_digits = str(S.Pi.n(3*10**5+2))[:-2] # alternative to above
pi_digits = pi_digits.replace(".", "")
def afind():
for k in range(1, len(pi_digits)):
sk = str(k)
if sk == pi_digits[2*k:2*k+len(sk)]:
print(k, end=", ")
afind() # Michael S. Branicky, Jan 30 2022
CROSSREFS
KEYWORD
base,more,nonn
AUTHOR
Gil Broussard, Dec 21 2008
EXTENSIONS
a(8) corrected by Paul Tek, Jun 09 2013
a(9) from Michael S. Branicky, Jan 30 2022
STATUS
approved