cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A244369 Palindromic right-angled primes.

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%I A244369 #14 May 22 2025 10:21:39
%S A244369 101,787,34543,7654567,345676543,34567876543
%N A244369 Palindromic right-angled primes.
%C A244369 Intersection of A002113 and A167842.
%C A244369 Intersection of A002385 and A135602.
%C A244369 The last term of this sequence is also the last term of A134811.
%e A244369 Illustration of a(6) = 34567876543, the last term of this sequence:
%e A244369 . . . . . . . . . . .
%e A244369 . . . . . 8 . . . . .
%e A244369 . . . . 7 . 7 . . . .
%e A244369 . . . 6 . . . 6 . . .
%e A244369 . . 5 . . . . . 5 . .
%e A244369 . 4 . . . . . . . 4 .
%e A244369 3 . . . . . . . . . 3
%e A244369 . . . . . . . . . . .
%e A244369 . . . . . . . . . . .
%e A244369 . . . . . . . . . . .
%o A244369 (Python)
%o A244369 from sympy import isprime
%o A244369 A244369 = []
%o A244369 for n in range(1,10):
%o A244369     for m in range(n-1,-1,-1):
%o A244369         l = ''.join([str(d) for d in range(n,m-1,-1)])
%o A244369         p = int(l+l[-2::-1])
%o A244369         if isprime(p):
%o A244369             A244369.append(p)
%o A244369     for m in range(n+1,10):
%o A244369         l = ''.join([str(d) for d in range(n,m+1)])
%o A244369         p = int(l+l[-2::-1])
%o A244369         if isprime(p):
%o A244369             A244369.append(p)
%o A244369 A244369 = sorted(A244369) # _Chai Wah Wu_, Aug 15 2014
%Y A244369 Cf. A000040, A002113, A002385, A134811, A135602, A167842.
%K A244369 nonn,base,fini,full
%O A244369 1,1
%A A244369 _Omar E. Pol_, Jun 26 2014