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A246135 Primes that are palindromic right angle numbers in base 9 2
173, 191, 373, 719, 50767, 1270271, 30890747159 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

50767 is in the list since it is prime and is equal to 76567 in base 9.

PROG

(Python)

from sympy import isprime

A246135 = []

for n in range(1, 9):

....for m in range(n-1, -1, -1):

........l = ''.join([str(d) for d in range(n, m-1, -1)])

........p = int(l+l[-2::-1], 9)

........if isprime(p):

............A246135.append(p)

....for m in range(n+1, 9):

........l = ''.join([str(d) for d in range(n, m+1)])

........p = int(l+l[-2::-1], 9)

........if isprime(p):

............A246135.append(p)

A246135 = sorted(A246135)

CROSSREFS

Cf. A246136, A244369.

Sequence in context: A259017 A097845 A261530 * A140002 A178652 A119567

Adjacent sequences:  A246132 A246133 A246134 * A246136 A246137 A246138

KEYWORD

nonn,base,full,fini

AUTHOR

Chai Wah Wu, Aug 15 2014

STATUS

approved

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Last modified January 20 03:32 EST 2019. Contains 319323 sequences. (Running on oeis4.)