A262943 Inverse of conjectured permutation A262942.

1, 2, 6, 3, 4, 8, 7, 5, 12, 9, 10, 14, 15, 11, 17, 13, 22, 18, 16, 19, 20, 23, 29, 24, 25, 21, 26, 28, 31, 38, 27, 30, 44, 32, 37, 43, 33, 34, 48, 35, 36, 39, 46, 54, 45, 40, 41, 49, 47, 50, 57, 52, 53, 42, 51, 59, 56, 63, 55, 58, 60, 61, 75, 65, 73, 67

Offset

1,2

Links

Robert Israel, Table of n, a(n) for n = 1..2500

Maple

N:= 1000: # to get all terms of A262942 before the first > N
V:= Vector(N):
W:= Vector(N):
S:= Vector(N):
firstav:= 1;
for n from 1 to N do
    forbid:= {seq(op([2*V[k]-V[2*k-n], 2*V[2*k-n]-V[k], (V[k]+V[2*k-n])/2]), k=ceil((n+1)/2)..n-1)};
    for v from firstav to N do
      if S[v] <> 0 and v = firstav then firstav:= v+1 fi;
      if S[v] = 0 and not member(v, forbid) then
        V[n]:= v;
        W[v]:= n;
        S[v]:= 1;
        break
      fi
    od;
    if v > N then break fi;
od:
seq(W[i], i=1..firstav-1); # Robert Israel, Nov 23 2015

Crossrefs

Cf. A262942, A229037.

Sequence in context: A236557 A359243 A379387 * A357735 A163892 A130108

Adjacent sequences: A262940 A262941 A262942 * A262944 A262945 A262946

Keyword

nonn

Author

Max Barrentine, Oct 05 2015

Extensions

Corrected and extended by Robert Israel, Nov 23 2015

Status

approved