A091697 Values of m corresponding to members of A088966.

2, 3, 5, 9, 17, 33, 35, 65, 129, 257, 513, 1025, 2049, 4097, 8193, 16385, 32769, 65537, 131073, 262145, 524289, 1048577

Offset: 1

Author

David Wasserman, Jan 29 2004

Keywords

• more
• nonn
• less

Comments

For every k >= 0, 2^k + 1 is in the sequence.

Examples

			a(2) = 3, corresponding to A088966(2) = 8 because A007947(8) = A007947(3+1) and A007947(3) = A007947(8+1).
		

Links

• Christian Hercher, On one of Erdős' Problems - An Efficient Search for Benelux Pairs, arXiv:2506.01099 [math.NT], 2025. See pp. 2, 13.

Programs

Maple

rad:= n -> convert(numtheory:-factorset(n), `*`):
count:= 0: lastr:= rad(1):
for n from 2 to 10^7 do
  newr:= rad(n);
  P[lastr, newr]:= n-1;
  if assigned(P[newr, lastr]) then
    count:= count+1; A[count]:= n-1; M[count]:= P[newr, lastr];
  fi;
  lastr:= newr;
od:
seq(M[n], n=1..count); # Robert Israel, Aug 11 2014

Extensions

a(13) from Robert Israel, Aug 11 2014

a(14)-a(22) from Hercher's paper by Martin Fuller, Jul 18 2025