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 A280427 #29 Mar 03 2024 10:15:03 %S A280427 3,5,167,359,839,1367,1847,2207,3719,5039,7919,1295027,3442949, %T A280427 9393929,13997519,21253931,49430861,84604517,95443991,237176657, %U A280427 329939369,384240581,487443401,633839777,904231061,1078193566319,1427186233199,1556727840719,1985193642959 %N A280427 a(n) is a prime, such that a(n) = p^d-2 where p is a prime and d is the number of digits of p. %C A280427 These numbers (proved for all p < 500) are a subset of A007528. For all even p, such numbers are a subset of A007528. The sequence is a subset of all numbers f(i) such that f(i) = i^d-2 (d - number of digits of integer i) and f(i) is a prime: e.g., f(15) is prime while f(15) = 15^2-2 = 223. %F A280427 a(n) = p^d-2, a(n) is prime, p is a prime and d is the number of digits of p. %e A280427 If p=5, then d=1 and a(1)=3; if p=7, then d=1 and a(2)=5; if p=13, then d=2 and a(3)=167; etc. %t A280427 Select[Array[#^IntegerLength@ # - 2 &@ Prime@ # &, 200], PrimeQ] (* _Michael De Vlieger_, Jan 03 2017 *) %Y A280427 Cf. A007528. %K A280427 nonn,base %O A280427 1,1 %A A280427 _Sergey Pavlov_, Jan 02 2017 %E A280427 More terms from _Michael De Vlieger_, Jan 03 2017