A087387 Palindromes in A087386.

2, 3, 7, 5, 11, 7, 727, 383, 727, 757, 727, 787, 929, 72727, 30103, 30703, 32323, 34543, 36563, 38183, 38783, 72727, 78487, 70507, 72727, 74747, 76367, 78787, 1242421, 90709, 94349, 94949, 96769, 98389, 1412141, 1242421, 1832381, 9923299, 7278727

Offset

1,1

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Example

Prime corresponding to the palindrome 121 is 727.

Prog

(Python)
from itertools import count, islice
from sympy import isprime
def A087387_gen(): # generator of terms
    for n in count(2):
        q =(c:=n-x)*x+int(str(c)[-2::-1] or 0) if n<(x:=10**(len(str(n>>1))-1))+(y:=10*x) else (c:=n-y)*y+int(str(c)[::-1] or 0)
        r = next(p for p in count(q+1, q) if isprime(p))
        if(s:=str(r))[:(t:=len(s)+1>>1)]==s[:-t-1:-1]:
            yield r
A087387_list = list(islice(A087387_gen(), 20)) # Chai Wah Wu, Jul 11 2024

Crossrefs

Cf. A087386.

Sequence in context: A110359 A092977 A057218 * A275205 A327093 A171039

Adjacent sequences: A087384 A087385 A087386 * A087388 A087389 A087390

Keyword

base,nonn

Author

Amarnath Murthy, Sep 09 2003

Extensions

More terms from David Wasserman, May 25 2005

Status

approved