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A365598 Near-repdigit primes with at least two 9's as the repeated digit, and ending in a distinct digit.

%I A365598 #24 Jun 21 2025 20:00:46
%S A365598 991,997,99991,9999991,99999999999999997,
%T A365598 999999999999999999999999999999991,
%U A365598 999999999999999999999999999999999999999999991
%N A365598 Near-repdigit primes with at least two 9's as the repeated digit, and ending in a distinct digit.
%C A365598 The usual definition of near-repdigit prime allows the distinct digit to be in any position, see A105975 for that (super) sequence.
%H A365598 Robert Israel, <a href="/A365598/b365598.txt">Table of n, a(n) for n = 1..15</a> (first 14 terms from Robert Price)
%e A365598 99991 is a term because all digits are equal to 9 except the last one.
%p A365598 R:= NULL: count:= 0:
%p A365598 for n from 3 to 999 do
%p A365598   for d in [9,3] do
%p A365598     if isprime(10^n - d) then
%p A365598       R:= R, 10^n-d; count:= count+1;
%p A365598     fi
%p A365598 od od:
%p A365598 R;
%Y A365598 Subsequence of A105975.
%Y A365598 Cf. A105976, A105978, A105979, A105980, A105982, A365592, A365596, A365597.
%K A365598 base,nonn
%O A365598 1,1
%A A365598 _Robert Price_, Sep 10 2023
%E A365598 Definition corrected by _M. F. Hasler_, Jun 20 2025