A305162 Numbers k such that A127417(k) = 1.

1, 2, 12, 20, 24, 80, 84, 260, 264, 384, 512, 684, 960, 1304, 1784, 2760, 4800, 4824, 5312, 5984, 6032, 9920, 10340, 10440, 10512, 13272, 14964, 15720, 18704, 23232, 24464, 26084, 27440, 27720, 28224

Offset

1,2

Comments

Numbers k such that for 2 <= m <= k-1, k is not congruent to -A127417(m) (mod m).

Links

Table of n, a(n) for n=1..35.

Example

a(3)=12 is a term because A127417(12)=1; thus 12 is not congruent to -1 (mod 2), -2 (mod 3), -2 (mod 4), -2 (mod 5), -2 (mod 6), -3 (mod 7), -2 (mod 8), -2 (mod 9), -4 (mod 10) or -3 (mod 11).

Maple

N:= 20000: # to get terms up to N
A127417[1]:= 1:
Res:= NULL:
for n from 2 to N do
  A127417[n]:= nops(select(t -> ((A127417[t]+n)/t)::integer, [$1..n-1]))
  if A127417[n] = 1 then Res:= Res, n fi
od:
Res;

Crossrefs

Cf. A127417.

Sequence in context: A277589 A069164 A067762 * A339709 A137311 A032407

Adjacent sequences: A305159 A305160 A305161 * A305163 A305164 A305165

Keyword

nonn

Author

Robert Israel, Aug 17 2018

Status

approved