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 A139182 #16 Apr 12 2024 16:13:43
%S A139182 50,51,125,15405,26205,226700,226701,226710,226711,513090,513091,
%T A139182 1351832,8210065
%N A139182 Numbers m such that pi(m) = d_1!!*d_2!!*...*d_k!! where d_1 d_2 ... d_k is the decimal expansion of m.
%C A139182 Numbers m with a product of the double-factorials of the digits equal to A000720(m).
%C A139182 If { m is in the sequence, 10 divides m and m+1 is composite } then m+1 is in the sequence. [Clarified by _N. J. A. Sloane_, Feb 06 2022]
%e A139182 pi(8210065)=8!!*2!!*1!!*0!!*0!!*6!!*5!!.
%t A139182 Select[Range[83*10^5],Times@@(IntegerDigits[#]!!)==PrimePi[#]&] (* _Harvey P. Dale_, Apr 12 2024 *)
%Y A139182 Cf. A066457, A006882.
%K A139182 base,nonn,less,more
%O A139182 1,1
%A A139182 _Farideh Firoozbakht_, Apr 19 2008