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 A297245 #4 Jan 17 2018 17:52:36
%S A297245 0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,2,1,0,
%T A297245 1,2,3,4,5,6,7,8,9,10,11,12,3,2,1,0,1,2,3,4,5,6,7,8,9,10,11,4,3,2,1,0,
%U A297245 1,2,3,4,5,6,7,8,9,10,5,4,3,2,1,0,1,2,3
%N A297245 Total variation of base-15 digits of n; see Comments.
%C A297245 Suppose that a number n has base-b digits b(m), b(m-1), ..., b(0). The base-b down-variation of n is the sum DV(n,b) of all d(i)-d(i-1) for which d(i) > d(i-1); the base-b up-variation of n is the sum UV(n,b) of all d(k-1)-d(k) for which d(k) < d(k-1). The total base-b variation of n is the sum TV(n,b) = DV(n,b) + UV(n,b). See A297330 for a guide to related sequences and partitions of the natural numbers:
%H A297245 Clark Kimberling, <a href="/A297245/b297245.txt">Table of n, a(n) for n = 1..10000</a>
%e A297245 2^20 in base 15: 1, 5, 10, 10, 5, 1; here, DV = 9 and UV = 9, so that a(2^20) = 18.
%t A297245 b = 15; z = 120; t = Table[Total@Flatten@Map[Abs@Differences@# &, Partition[IntegerDigits[n, b], 2, 1]], {n, z}] (* cf. Michael De Vlieger, e.g. A037834 *)
%Y A297245 Cf. A297243, A297244, A297330.
%K A297245 nonn,base,easy
%O A297245 1,18
%A A297245 _Clark Kimberling_, Jan 17 2018