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A296712 Numbers whose base-10 digits d(m), d(m-1), ..., d(0) have #(rises) = #(falls); see Comments. 116

%I #7 Jan 27 2023 19:24:14

%S 1,2,3,4,5,6,7,8,9,11,22,33,44,55,66,77,88,99,101,102,103,104,105,106,

%T 107,108,109,111,120,121,130,131,132,140,141,142,143,150,151,152,153,

%U 154,160,161,162,163,164,165,170,171,172,173,174,175,176,180,181

%N Numbers whose base-10 digits d(m), d(m-1), ..., d(0) have #(rises) = #(falls); see Comments.

%C A rise is an index i such that d(i) < d(i+1); a fall is an index i such that d(i) > d(i+1). The sequences A296712-A296714 partition the natural numbers.

%C ****

%C Guide to related sequences:

%C Base #(rises) = #(falls) #(rises) > #(falls) #(rises) < #(falls)

%C 2 A005408 (none) A005843

%C 3 A296691 A296692 A296693

%C 4 A296694 A296695 A296696

%C 5 A296697 A296698 A296699

%C 6 A296700 A296701 A296702

%C 7 A296703 A296704 A296705

%C 8 A296706 A296707 A296708

%C 9 A296709 A296710 A296711

%C 10 A296712 A296713 A296714

%C 11 A296744 A296745 A296746

%C 12 A296747 A296748 A296749

%C 13 A296750 A296751 A296752

%C 14 A296753 A296754 A296755

%C 15 A296756 A296757 A296758

%C 16 A296759 A296760 A296761

%C 20 A296762 A296763 A296764

%C 60 A296765 A296766 A296767

%H Clark Kimberling, <a href="/A296712/b296712.txt">Table of n, a(n) for n = 1..10000</a>

%e The base-10 digits of 181 are 1,8,1; here #(rises) = 1 and #(falls) = 1, so 181 is in the sequence.

%t z = 200; b = 10; d[n_] := Sign[Differences[IntegerDigits[n, b]]];

%t Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296712 *)

%t Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &] (* A296713 *)

%t Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &] (* A296714 *)

%Y Cf. A296713, A296714, A296712.

%K nonn,base,easy

%O 1,2

%A _Clark Kimberling_, Jan 08 2018

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Last modified April 24 07:06 EDT 2024. Contains 371920 sequences. (Running on oeis4.)