A344308 Numbers k such that A205791(k) = k+1.

1, 2, 3, 5, 6, 7, 10, 13, 14, 15, 17, 19, 21, 23, 26, 29, 30, 34, 35, 37, 38, 39, 42, 43, 46, 47, 51, 53, 57, 58, 59, 65, 67, 69, 70, 73, 74, 78, 79, 83, 85, 86, 87, 89, 91, 94, 95, 97, 102, 103, 105, 106, 107, 109, 111, 113, 114, 115, 118, 119, 127, 129, 130, 133, 134, 137, 138, 139, 141, 145

Offset: 1

Author

Robert Israel, May 14 2021

Keywords

• nonn

Examples

			a(6) = 7 is a term because A205791(7) = 8.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..1258

Crossrefs

Cf. A205791.

Subset of A005117.

Programs

Maple

N:= 200: # for terms <= N
V:= Vector(N):
count:= 0:
for k from 1 while count < N do
  for j from 1 to k-1 while count < N do
    Q:= select(t -> t <= N and V[t] = 0, numtheory:-divisors(k^5-j^5));
    if Q <> {} then
       newcount:= nops(Q);
       count:= count + newcount;
       V[convert(Q, list)]:= k;
    fi
od od:
select(t -> V[t] = t+1, [$1..N]);

Mathematica

Select[Range@200,(k=1;While[FreeQ[Mod[Table[k^5-j^5,{j,k-1}],#],0],k++];k)==#+1&] (* Giorgos Kalogeropoulos, May 14 2021 *)