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A058993
Numbers m such that 5^m reversed is a prime.
8
1, 3, 26, 36, 43, 66, 76, 149, 511, 885, 3767, 18157, 20516, 26316
OFFSET
1,2
MATHEMATICA
Do[ If[ PrimeQ[ ToExpression[ StringReverse[ ToString[5^n] ] ] ], Print[n] ], {n, 1, 3000} ]
PROG
(Python)
from sympy import isprime
k, m, A058993_list = 1, 5, []
while k <= 10**3:
if isprime(int(str(m)[::-1])):
A058993_list.append(k)
k += 1
m *= 5 # Chai Wah Wu, Mar 09 2021
(PARI) isok(m) = isprime(fromdigits(Vecrev(digits(5^m)))) \\ Mohammed Yaseen, Jul 20 2022
CROSSREFS
Numbers m such that k^m reversed is prime: A057708 (k=2), A350441 (k=4), this sequence (k=5), A058994 (k=7), A350442 (k=8), A058995 (k=13).
Sequence in context: A221616 A321222 A062181 * A358352 A083109 A191590
KEYWORD
nonn,base,more
AUTHOR
Robert G. Wilson v, Jan 17 2001
EXTENSIONS
a(12)-a(14) from Michael S. Branicky, Apr 01 2023
STATUS
approved