A073547 Numbers k such that antid(k) = antid(k+1), where antid(k) = A066272(k).

1, 3, 8, 10, 14, 19, 20, 22, 27, 29, 40, 42, 46, 49, 52, 58, 65, 70, 74, 75, 82, 87, 90, 91, 94, 102, 103, 112, 116, 118, 122, 124, 131, 135, 148, 149, 151, 154, 157, 159, 171, 180, 183, 187, 188, 198, 204, 205, 208, 212, 213, 214, 217, 220, 222, 227, 231, 232

Offset: 1

Author

Jason Earls, Aug 31 2002

Keywords

• easy
• nonn

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A066272.

Programs

Maple

N:= 1000: # to get all terms <= N-1
V:= Vector(N):
for k from 1 to floor(N/3) do
  R1:= [seq(i, i=3*k .. N, 2*k)];
  V[R1]:= map(`+`,V[R1],1);
  R2:= [seq(i, i=3*k+1 .. N, 2*k+1)];
  V[R2]:= map(`+`,V[R2],1);
  R3:= [seq(i,i=3*k+2 .. N, 2*k+1)];
  V[R3]:= map(`+`,V[R3],1);
od:
select(t -> V[t]=V[t+1], [$1..N-1]); # Robert Israel, Sep 26 2016

Mathematica

at[n_] := Count[Flatten[Quotient[#, Rest[Select[Divisors[#], OddQ]]] & /@ (2 n + Range[-1, 1])], Except[1]]; Select[Range[232], at[#] == at[# + 1] &] (* Jayanta Basu, Jul 01 2013 *)