

A297142


Numbers whose base8 digits d(m), d(m1),..., d(0) have m=0 or else d(i) = d(i+1) for some i in {0,1,...,m1}.


5



1, 2, 3, 4, 5, 6, 7, 9, 18, 27, 36, 45, 54, 63, 64, 72, 73, 74, 75, 76, 77, 78, 79, 82, 91, 100, 109, 118, 127, 128, 137, 144, 145, 146, 147, 148, 149, 150, 151, 155, 164, 173, 182, 191, 192, 201, 210, 216, 217, 218, 219, 220, 221, 222, 223, 228, 237, 246
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OFFSET

1,2


COMMENTS

These numbers comprise the complement of the set of numbers in the union of A297140 and A297141.
Differs from A044819 first for 513 = 1001_8, which has two consecutive equal digits and is in this sequence, but has two runs of equal length (1), and is not in A044819.  R. J. Mathar, Jan 17 2018


LINKS

Table of n, a(n) for n=1..58.


EXAMPLE

Base8 digits of 5000: 1,1,6,1,0, so that 5000 is in the sequence.


MAPLE

read("transforms") :
isA297142 := proc(n)
local dgs, ud;
dgs := convert(n, base, 8) ;
if nops(dgs) < 2 then
return true;
end if;
if 0 in DIFF(dgs) then
true;
else
false;
end if;
end proc:
for n from 1 to 300 do
if isA297142(n) then
printf("%d, ", n) ;
end if;
end do: # R. J. Mathar, Jan 18 2018


MATHEMATICA

a[n_, b_] := Sign[Differences[IntegerDigits[n, b]]]; z = 300;
b = 8; t = Table[a[n, b], {n, 1, 10*z}];
u = Select[Range[z], ! MemberQ[t[[#]], 0] && First[t[[#]]] == 1 &] (* A297140 *)
v = Select[Range[z], ! MemberQ[t[[#]], 0] && First[t[[#]]] == 1 &] (* A297141 *)
Complement[Range[z], Union[u, v]] (* A297142 *)


CROSSREFS

Cf. A297140, A297142.
Sequence in context: A039126 A083376 A044957 * A044819 A048305 A043711
Adjacent sequences: A297139 A297140 A297141 * A297143 A297144 A297145


KEYWORD

nonn,easy,base


AUTHOR

Clark Kimberling, Jan 15 2018


STATUS

approved



