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 A135104 #11 Sep 24 2016 04:28:15
%S A135104 1,4,5,10,15,24,17,28,27,60,31,36,81,70,71,68,117,96,37,120,81,100,
%T A135104 139,192,97,176,123,174,205,128,193,126,137,220,201,216,133,196,397,
%U A135104 296,189,396,321,256,305,280,331,396,445,292,313,256,481,556,417,326,553,256
%N A135104 Digital sum (base the n-th prime) of n^4.
%H A135104 G. C. Greubel, <a href="/A135104/b135104.txt">Table of n, a(n) for n = 1..1000</a>
%F A135104 a(n) = ds_prime(n)(n^4), where ds_prime(n) = digital sum base the n-th prime.
%F A135104 a(n) = n^4 - (prime(n)-1)*Sum{k>0} ( floor(n^4/prime(n)^k) ).
%e A135104 a(2) = ds_prime(2)(2^4) = ds_3(16) = 1+2+1 = 4;
%e A135104 a(6) = ds_prime(6)(6^4) = ds_13(1296) = 7+8+9 = 24.
%t A135104 Table[Total[IntegerDigits[n^4, Prime[n]]], {n, 50}] (* _G. C. Greubel_, Sep 23 2016 *)
%o A135104 (PARI) a(n) = vecsum(digits(n^4, prime(n))); \\ _Michel Marcus_, Sep 24 2016
%Y A135104 Cf. A000040, A007953, A054899, A075771, A131451, A133620, A133900, A134599.
%K A135104 nonn,base
%O A135104 1,2
%A A135104 _Hieronymus Fischer_, Dec 24 2007