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 A123111 #16 Jun 18 2017 02:23:11
%S A123111 5,173,2467,17489,81401,287965,840743,2130497,4842829,10101101,
%T A123111 19649675,36082513,63122177,105954269,171622351,269488385,411763733,
%U A123111 614115757,896355059,1283208401,1805182345,2499522653,3411274487,4594448449
%N A123111 1+n^2+n^3+n^5+n^7; 10101101 in base n.
%C A123111 4th row, A(4,n), of the infinite array A(k,n) = 1 + SUM[i=1..k]n^prime(i). If we deem prime(0) = 1, the array is A(k,n) = SUM[i=0..k]n^prime(i). The first row is A002522 = 1 + n^2. The second row is A098547 = 1 + n^2 + n^3. Row 4 (the current sequence) is prime for n = 1, 2, 3, 4, 5, 7, 10, 18, 19, 23, 25.
%H A123111 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (8,-28,56,-70,56,-28,8,-1).
%F A123111 a(n) = 1 + n^2 + n^3 + n^5 + n^7 = 10101101 (base n) = 1 + SUM[i=1..4]n^prime(i).
%F A123111 G.f.: -x*(x^7-9*x^6-127*x^5-1227*x^4-2317*x^3-1223*x^2-133*x-5) / (x-1)^8. - _Colin Barker_, Sep 02 2014
%F A123111 a(n+7)-7*a(n+6)+21*a(n+5)-35*a(n+4)+35*a(n+3)-21*a(n+2)+7*a(n+1)-a(n)=5040. - _Robert Israel_, Sep 02 2014
%p A123111 seq(1 + n^2 + n^3 + n^5 + n^7, n=1..100); # _Robert Israel_, Sep 02 2014
%t A123111 Table[Total[n^Prime[Range[4]]]+1,{n,30}] (* _Harvey P. Dale_, Jan 01 2014 *)
%o A123111 (PARI) Vec(-x*(x^7-9*x^6-127*x^5-1227*x^4-2317*x^3-1223*x^2-133*x-5)/(x-1)^8 + O(x^100)) \\ _Colin Barker_, Sep 02 2014
%Y A123111 Cf. A000040, A002522, A098547.
%K A123111 easy,nonn
%O A123111 1,1
%A A123111 _Jonathan Vos Post_, Sep 28 2006