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A297278 Numbers whose base-12 digits have greater up-variation than down-variation; see Comments. 4
14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 27, 28, 29, 30, 31, 32, 33, 34, 35, 40, 41, 42, 43, 44, 45, 46, 47, 53, 54, 55, 56, 57, 58, 59, 66, 67, 68, 69, 70, 71, 79, 80, 81, 82, 83, 92, 93, 94, 95, 105, 106, 107, 118, 119, 131, 146, 147, 148, 149, 150, 151 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Suppose that 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 the guide at A297330.

LINKS

Clark Kimberling, Table of n, a(n) for n = 1..10000

EXAMPLE

151 in base-12:  1,0,7, having DV = 1, UV = 7, so that 151 is in the sequence.

MATHEMATICA

g[n_, b_] := Map[Total, GatherBy[Differences[IntegerDigits[n, b]], Sign]];

x[n_, b_] := Select[g[n, b], # < 0 &]; y[n_, b_] := Select[g[n, b], # > 0 &];

b = 12; z = 2000; p = Table[x[n, b], {n, 1, z}]; q = Table[y[n, b], {n, 1, z}];

w = Sign[Flatten[p /. {} -> {0}] + Flatten[q /. {} -> {0}]];

Take[Flatten[Position[w, -1]], 120]   (* A297276 *)

Take[Flatten[Position[w, 0]], 120]    (* A297277 *)

Take[Flatten[Position[w, 1]], 120]    (* A297278 *)

CROSSREFS

Cf. A297330, A297276, A297277.

Sequence in context: A004455 A142865 A089838 * A296748 A270042 A332924

Adjacent sequences:  A297275 A297276 A297277 * A297279 A297280 A297281

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling, Jan 17 2018

STATUS

approved

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Last modified September 26 15:53 EDT 2021. Contains 347668 sequences. (Running on oeis4.)