A246135 Primes that are palindromic right angle numbers in base 9.

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

Offset: 1

Author

Chai Wah Wu, Aug 15 2014

Keywords

• nonn
• base
• full
• fini

Examples

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

Crossrefs

Cf. A246136, A244369.

Programs

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)