Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #7 Jan 19 2018 16:22:54
%S 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,2,3,4,5,6,7,8,9,10,11,12,0,0,0,1,2,3,
%T 4,5,6,7,8,9,10,11,0,0,0,0,1,2,3,4,5,6,7,8,9,10,0,0,0,0,0,1,2,3,4,5,6,
%U 7,8,9,0,0,0,0,0,0,1,2,3,4,5,6,7,8,0
%N Up-variation of the base-14 digits of n; see Comments.
%C 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). Every positive integer occurs infinitely many times. See A297330 for a guide to related sequences and partitions of the natural numbers.
%H Clark Kimberling, <a href="/A297241/b297241.txt">Table of n, a(n) for n = 1..10000</a>
%e 18 in base 14: 1,4; here UV = 3, so that a(18) = 3.
%t g[n_, b_] := Differences[IntegerDigits[n, b]];
%t b = 14; z = 120; Table[-Total[Select[g[n, b], # < 0 &]], {n, 1, z}]; (* A297240 *)
%t Table[Total[Select[g[n, b], # > 0 &]], {n, 1, z}]; (* A297241 *)
%Y Cf. A297240, A297242, A297330.
%K nonn,base,easy
%O 1,17
%A _Clark Kimberling_, Jan 17 2018