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 A179802 #24 Mar 08 2022 08:14:59
%S A179802 3,9,3,9,3,9,3,9,3,3,9,9,3,9,3,3,3,9,9,3,9,9,3,3,9,3,9,3,9,3,9,3,3,9,
%T A179802 3,9,9,9,3,3,3,9,3,9,3,9,9,9,3,9,3,3,9,3,3,3,3,9,9,3,9,3,9,3,9,3,9,9,
%U A179802 3,9,3,3,9,9,9,3,3,9,3,9,3,9,3,9,9,3,3
%N A179802 Digital root of A179545.
%C A179802 Because every term in A179545 is a multiple of 3, each term of this sequence is 3 or 9. - _Nathaniel Johnston_, May 04 2011
%C A179802 a(n) = 3 if and only if prime(n) == 2 (mod 3); otherwise a(n) = 9. - _Charles R Greathouse IV_, May 19 2011
%H A179802 Nathaniel Johnston, <a href="/A179802/b179802.txt">Table of n, a(n) for n = 1..10000</a>
%F A179802 a(n) = A010888(A179545(n)). - _Michel Marcus_, Mar 08 2022
%p A179802 read("transforms") ; A010888 :=proc(n) local a; a := digsum(n) ; if a > 9 then return procname(a) ; else return a; end if; end proc:
%p A179802 A179545 := proc(n) local p; p := ithprime(n); 3*p*(p-1)/2 ; end proc:
%p A179802 A179802 := proc(n) A010888(A179545(n)) ; end proc:
%p A179802 seq(A179802(n),n=1..180) ; # _R. J. Mathar_, Oct 03 2010
%o A179802 (PARI) apply(p->if(p%3==2,3,9),primes(10000)) \\ _Charles R Greathouse IV_, May 19 2011
%Y A179802 Cf. A000040, A010888, A179545.
%K A179802 easy,nonn,base
%O A179802 1,1
%A A179802 _Odimar Fabeny_, Jul 27 2010
%E A179802 More terms from _R. J. Mathar_, Oct 03 2010