cp's OEIS Frontend

A384015 Primes with at least two identical trailing digits and at least two identical leading digits.

%I A384015 #11 May 20 2025 15:48:29
%S A384015 11,11177,11299,11311,11399,11411,11633,11677,11699,11777,11833,11933,
%T A384015 22111,22133,22277,22433,22511,22699,22777,22811,22877,33199,33211,
%U A384015 33311,33377,33533,33577,33599,33811,33911,44111,44533,44633,44699,44711,44777,55333,55399
%N A384015 Primes with at least two identical trailing digits and at least two identical leading digits.
%t A384015 Select[Prime[Range[5,6000]],Part[d=IntegerDigits[#],l=IntegerLength[#]]==Part[d,l-1] && Part[d,1]==Part[d,2] &]
%o A384015 (Python)
%o A384015 from itertools import count, islice
%o A384015 from sympy import isprime
%o A384015 def A384015_gen(): # generator of terms
%o A384015     yield 11
%o A384015     for n in count(2):
%o A384015         yield from filter(isprime,(i+j+k for i in range(11*10**(n-2),11*10**(n-1),11*10**(n-2)) for j in range(0,10**(n-2),100) for k in (11,33,77,99)))
%o A384015 A384015_list = list(islice(A384015_gen(),38)) # _Chai Wah Wu_, May 20 2025
%Y A384015 Cf. A383978, A384013, A384016.
%Y A384015 Subsequence of A050758.
%K A384015 nonn,base
%O A384015 1,1
%A A384015 _Stefano Spezia_, May 17 2025