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

9, 233, 1614, 9218, 27755974, 81259258, 120526011, 238732548, 651265325, 783609697

Offset

1,1

Links

Table of n, a(n) for n=1..10.

Example

a(1) = 9 because 9 occurs at offset (9-4) 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(5, len(pi_digits)):
        sk = str(k)
        if sk == pi_digits[k-4:k-4+len(sk)]:
            print(k, end=", ")
afind() # Michael S. Branicky, Jan 30 2022

Crossrefs

Cf. A057679, A057680, A109513, A109514, A153221, A153224.

Sequence in context: A152101 A230178 A165389 * A276536 A288683 A302914

Adjacent sequences: A153220 A153221 A153222 * A153224 A153225 A153226

Keyword

base,more,nonn

Author

Gil Broussard, Dec 21 2008

Extensions

a(5)-a(10) from Michael S. Branicky, Jan 30 2022

Status

approved