This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A297269 Numbers whose base-9 digits have greater up-variation than down-variation; see Comments. 4
 11, 12, 13, 14, 15, 16, 17, 21, 22, 23, 24, 25, 26, 31, 32, 33, 34, 35, 41, 42, 43, 44, 51, 52, 53, 61, 62, 71, 83, 84, 85, 86, 87, 88, 89, 92, 93, 94, 95, 96, 97, 98, 101, 102, 103, 104, 105, 106, 107, 110, 111, 112, 113, 114, 115, 116, 119, 120, 121, 122 (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 122 in base-9:  1,4,5, having DV = 0, UV = 4, so that 122 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 = 9; 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]   (* A297267 *) Take[Flatten[Position[w, 0]], 120]    (* A297268 *) Take[Flatten[Position[w, 1]], 120]    (* A297269 *) CROSSREFS Cf. A297330, A297267, A297268. Sequence in context: A162672 A110403 A119247 * A296710 A297143 A138595 Adjacent sequences:  A297266 A297267 A297268 * A297270 A297271 A297272 KEYWORD nonn,base,easy AUTHOR Clark Kimberling, Jan 15 2018 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 7 00:16 EST 2019. Contains 329812 sequences. (Running on oeis4.)