A032858
Numbers whose base-3 representation Sum_{i=0..m} d(i)*3^i has d(m) > d(m-1) < d(m-2) > ...
Original entry on oeis.org
0, 1, 2, 3, 6, 7, 10, 11, 19, 20, 23, 30, 33, 34, 57, 60, 61, 69, 70, 91, 92, 100, 101, 104, 172, 173, 181, 182, 185, 208, 209, 212, 273, 276, 277, 300, 303, 304, 312, 313, 516, 519, 520, 543, 546, 547, 555, 556, 624, 627, 628, 636, 637
Offset: 1
The base-3 representation of the initial terms is 0, 1, 2, 10, 20, 21, 101, 102, 201, 202, 212, 1010, 1020, 1021, 2010, 2020, 2021, 2120, 2121, 10101, 10102, ...
Cf.
A306105 for these terms written in base 3.
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sdQ[n_]:=Module[{s=Sign[Differences[IntegerDigits[n, 3]]]}, s==PadRight[{}, Length[s], {-1, 1}]]; Select[Range[0, 700], sdQ] (* Vincenzo Librandi, Oct 06 2018 *)
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is(n,b=3)=!for(i=2,#n=digits(n,b),(n[i-1]-n[i])*(-1)^i>0||return) \\ M. F. Hasler, Oct 05 2018
Definition edited, cross-references and a(1) = 0 inserted by
M. F. Hasler, Oct 05 2018
A306105
Numbers with digits in {0,1,2} such that every other digit is strictly less than its neighbors.
Original entry on oeis.org
0, 1, 2, 10, 20, 21, 101, 102, 201, 202, 212, 1010, 1020, 1021, 2010, 2020, 2021, 2120, 2121, 10101, 10102, 10201, 10202, 10212, 20101, 20102, 20201, 20202, 20212, 21201, 21202, 21212, 101010, 101020, 101021, 102010, 102020, 102021, 102120, 102121
Offset: 1
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{A=[0,1,2]; F=[1,1]; for(n=0,4, F=[F[2],vecsum(F)]; for(k=1,3, T=max(k*10,21)*10^n; A=concat(A,apply(t->t+T,A[F[2]-1+if(k>2,F*[2,-1]~)..vecsum(F)-2]))));A}
A306106
Numbers with digits in {0,1,2,3} such that every other digit is strictly less than its neighbors.
Original entry on oeis.org
0, 1, 2, 3, 10, 20, 21, 30, 31, 32, 101, 102, 103, 201, 202, 203, 212, 213, 301, 302, 303, 312, 313, 323, 1010, 1020, 1021, 1030, 1031, 1032, 2010, 2020, 2021, 2030, 2031, 2032, 2120, 2121, 2130, 2131, 2132, 3010, 3020, 3021, 3030, 3031, 3032, 3120, 3121, 3130, 3131, 3132, 3230, 3231, 3232, 10101, 10102, 10103
Offset: 1
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A(Nmax=100, K=3, A=[0..K], i=vector(2*K, i, max(1, i-K+1)), c(T, v)=apply(t->t+T, v))={for(n=0, oo, for(k=10, K*11, if(k%10
A032863
Numbers whose base-8 representation Sum_{i=0..m} d(i)*8^i has d(m) > d(m-1) < d(m-2) > ...
Original entry on oeis.org
0, 1, 2, 3, 4, 5, 6, 7, 8, 16, 17, 24, 25, 26, 32, 33, 34, 35, 40, 41, 42, 43, 44, 48, 49, 50, 51, 52, 53, 56, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 71, 129, 130, 131, 132, 133, 134, 135, 138, 139, 140, 141, 142, 143, 193, 194, 195
Offset: 1
From _M. F. Hasler_, Oct 05 2018: (Start)
The base-8 representation of 7, 8, 16, 17, 24, 25, 26, 32, 33 is 7, 10, 20, 21, 30, 31, 32, 40, 41.
Numbers 61, 62, 65, 66, ..., 70, 71, 129, 130, ... have the base-8 expansion 76, 77, 101, 102, ..., 106, 107, 201, 202, ... (End)
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sdQ[n_]:=Module[{s=Sign[Differences[IntegerDigits[n, 8]]]}, s==PadRight[{}, Length[s], {-1, 1}]]; Select[Range[0, 700], sdQ] (* Vincenzo Librandi, Oct 06 2018 *)
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is(n)=!for(i=2,#n=digits(n,8),(n[i-1]-n[i])*(-1)^i>0||return) \\ M. F. Hasler, Oct 05 2018
Showing 1-4 of 4 results.
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