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 A055738 #24 Aug 05 2025 03:42:07
%S A055738 0,3,6,13,39,167,900,4769,28389,180530,1209319,8398279,60070591,
%T A055738 441296837,3314576488
%N A055738 Number of prime quadruples < 10^n, where a prime quadruple means 4 successive primes {p, p', p'', p'''} with p''' = p + 8.
%D A055738 J. Recreational Math., vol. 23, No. 2, 1991, p. 97.
%H A055738 <a href="/index/Pri#primepop">Index entries for sequences related to numbers of primes in various ranges</a>
%e A055738 For n=2 the quadruples are 3,5,7,11; 5,7,11,13; 11,13,17,19.
%p A055738 with(numtheory): x := 1229; t1 := [seq(ithprime(i),i=1..x)]; c := 0: for i from 1 to x-3 do if t1[i]+8 = t1[i+3] then c := c+1; fi; od: c; # the values of x to use are given by A006880.
%t A055738 x=168; a=Table[ Prime[ n ], {n, 1, x} ]; c=0; Do[ If[ a[ [ n ] ]+8==a[ [ n+3 ] ], c++ ], {n, 1, x-3} ]; c (* The values of x to use are given by A006880. *)
%Y A055738 Cf. A055737, A006880.
%K A055738 nonn,more,hard
%O A055738 1,2
%A A055738 _Robert G. Wilson v_, Jun 09 2000
%E A055738 a(8)-a(9) from _Jud McCranie_, Oct 08 2000.
%E A055738 a(10)-a(12) from _Bert Dobbelaere_, Apr 17 2019
%E A055738 a(13)-a(15) from _Charles R Greathouse IV_, Feb 12 2022