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 A212328 #10 May 13 2013 01:54:21 %S A212328 1,1,4,4,58,139,139,1597,1597,8158,8158,67207,67207,598648,2192971, %T A212328 6975940,21324847,21324847,21324847,408745336,1571006803,8544575605, %U A212328 29465282011,29465282011,217751639665,500181176146,1347469785589,6431201442247,6431201442247 %N A212328 Smallest k such that k^3 + 17 is divisible by 3^n. %C A212328 This sequence is generalizable : the smallest k such that k^3 + p is divisible by 3^n exists if the prime p is congruent to + - 1 mod 18. For example, the sequence with p = 19 is given by {2, 2, 2, 20, 20, 20, 263, 992, 3179, 16301, 55667, 173765, 528059, …}. (See A129805). This sequence is given with the smallest p = 17. %H A212328 Charles R Greathouse IV, <a href="/A212328/b212328.txt">Table of n, a(n) for n = 1..1000</a> %e A212328 a(4) = 4 because 4^3 + 17 = 81 is divisible by 3^4. %p A212328 with(numtheory):for n from 1 to 20 do:i:=0:for x from 1 to 10^8 while(i=0) do: z:= x^3 + 17:if irem(z,3^n)=0 then i:=1: printf ( "%d %d \n",n,x):else fi:od:od: %o A212328 (PARI) print1(k=1);for(n=2,100,if(Mod(k,3^n)^3!=-17,k+=3^(n-2)* if(Mod(k+3^(n-2),3^n)^3==-17,1,2));print1(", "k)) \\ _Charles R Greathouse IV_, May 14 2012 %Y A212328 Cf. A129805. %K A212328 nonn,easy %O A212328 1,3 %A A212328 _Michel Lagneau_, May 14 2012 %E A212328 a(20)-a(29) from _Charles R Greathouse IV_, May 14 2012