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URL: https://oeis.org/A378625

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A378625
The first subsequence starting at the first digit after the decimal point in the decimal expansion of Pi that is divisible by n.
0
1, 14, 141, 141592, 1415, 141592653589793238, 14, 141592, 141592653, 14159265358979323846264338327950, 141592, 1415926535897932384626433832795028, 14159265358979, 14, 14159265, 1415926535897932384, 141592653589793, 141592653589793238, 141592653589793238462
OFFSET
1,2
COMMENTS
For every positive integer n there exists a contiguous subsequence of the decimal expansion of Pi that is divisible by n (conjectured).
FORMULA
a(n) = n * A088143(n). - Alois P. Heinz, Dec 05 2024
EXAMPLE
a(3) = 141 is the first integer in the sequence that is divisible by 3.
a(6) = 141592653589793238 is the first integer in the sequence that is divisibe by 6.
PROG
(Python)
from mpmath import mp
mp.dps = 1000000
pi_digits = str(mp.pi)[2:]
def first_divisible(n):
current_number = 0
for digit in pi_digits:
current_number = current_number * 10 + int(digit)
if current_number % n == 0:
return current_number
return None
results = [first_divisible(n) for n in range(1, 21)]
print(results)
CROSSREFS
Cf. A014777 (if start can move).
Sequence in context: A011547 A011548 A039916 * A387233 A241217 A159500
KEYWORD
nonn,base
AUTHOR
Simon R Blow, Dec 02 2024
STATUS
approved