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 A287895 #16 Jun 30 2017 20:39:02
%S A287895 4,13,12,3,61,42,50,39,43,80,65,89,180,110,146,160,156,187,88,118,258,
%T A287895 243,244,282,287,189,343,311,203,410,219,467,473,274,384,535,406,484,
%U A287895 54,825,310,558,551,375,886,659,539,515,294,914,764,478,774,757,823
%N A287895 Differences of A287894.
%C A287895 The first two negative terms are a(99) = -239 and a(999) = -5966. - _Giovanni Resta_, Jun 07 2017
%H A287895 Robert Israel, <a href="/A287895/b287895.txt">Table of n, a(n) for n = 1..1000</a>
%e A287895 Take the differences of 1,5,18,30,... => 4,13,12,...
%p A287895 ds:= n -> convert(convert(n,base,10),`+`):
%p A287895 f:= n -> add(ds(k^n),k=1..n):
%p A287895 A287894:= map(f, [$1..101]);
%p A287895 A287894[2..101] - A287894[1..100]; # _Robert Israel_, Jun 30 2017
%t A287895 s[n_] := Sum[Total@IntegerDigits[k^n], {k, n}]; Differences@ Array[s, 60] (* _Giovanni Resta_, Jun 07 2017 *)
%Y A287895 Cf. A287894.
%K A287895 sign,base
%O A287895 1,1
%A A287895 _Marian Kraus_, Jun 02 2017