

A101544


Smallest permutation of the natural numbers with a(3*k2)+a(3*k1)=a(3*k), k>0.


4



1, 2, 3, 4, 5, 9, 6, 7, 13, 8, 10, 18, 11, 12, 23, 14, 15, 29, 16, 17, 33, 19, 20, 39, 21, 22, 43, 24, 25, 49, 26, 27, 53, 28, 30, 58, 31, 32, 63, 34, 35, 69, 36, 37, 73, 38, 40, 78, 41, 42, 83, 44, 45, 89, 46, 47, 93, 48, 50, 98, 51, 52, 103, 54, 55, 109, 56, 57, 113, 59, 60
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OFFSET

1,2


COMMENTS

Inverse: a101545; a101546(n) = a(a(n)).


LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000
Index entries for sequences that are permutations of the natural numbers


MAPLE

N:= 100: # to get a(1) .. a(N)
S:= {$1..N}:
for n from 1 to N do
if n mod 3 = 0 then A[n] := A[n1]+A[n2]
else A[n]:= min(S)
fi;
S:= S minus {A[n]};
od:
seq(A[i], i=1..N); # Robert Israel, Feb 07 2016


MATHEMATICA

Fold[Append[#1, If[Divisible[#2, 3], #1[[1]] + #1[[2]], Min@Complement[Range[Max@#1 + 1], #1]]] &, {1}, Range[2, 71]] (* Ivan Neretin, Feb 05 2016 *)


CROSSREFS

Sequence in context: A105950 A227778 A166276 * A171100 A240062 A255129
Adjacent sequences: A101541 A101542 A101543 * A101545 A101546 A101547


KEYWORD

nonn


AUTHOR

Reinhard Zumkeller, Dec 06 2004


STATUS

approved



