A246135 Primes that are palindromic right angle numbers in base 9

173, 191, 373, 719, 50767, 1270271, 30890747159

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: A097845 A364937 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