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.
%I A319017 #21 Jan 21 2025 10:53:30
%S A319017 21347,2213347,2213447,21334447,21344447,21344777,22133477,213334477,
%T A319017 221344477,2134444777,22133344447,221344477777,2133344447777,
%U A319017 2133347777777,2213447777777,22133344447777,213344447777777,221333447777777,22133344447777777
%N A319017 Prime numbers which satisfy the regex m1{1,m1}m2{1,m2}m3{1,m3}m4{1,m4}m5{1,m5} where mi are one-digit Lucas numbers.
%C A319017 mi=Lucas numbers sequence(i), i.e., m1=2, m2=1, m3=3 and so on.
%C A319017 There are 168 = 2*1*3*4*7 numbers matching this regular expression, of which 19 are prime. - _Charles R Greathouse IV_, Jan 21 2025
%e A319017 The prime number 2213447 belongs to this sequence as 2, 1, 3, 4 and 7 are the one-digit Lucas numbers (ordered as in Lucas number sequence) and each digit k is repeated at most k times (including itself), in accordance with the regex described in the sequence name (2 repeated two times, 1 one time, 3 repeated one time, 4 repeated two times and 7 one time).
%e A319017 The prime number 22133344447777777 is the best example, as each one-digit Lucas number k is repeated exactly k times.
%Y A319017 Subsequence of A178550.
%Y A319017 Cf. A000032.
%K A319017 nonn,base,fini,full
%O A319017 1,1
%A A319017 _Pierandrea Formusa_, Sep 07 2018