A378481 Integers k such that A378414(k) == k (mod A066417(k)).

33, 77, 153, 372, 1540, 2300, 2692, 2736, 7812, 8721, 12593, 26025, 26481, 27972, 39321, 64009, 104409, 175441, 325180, 335616, 422593, 455625, 564376, 575040, 756460, 800073, 1104521, 2180545, 2304332, 3502665, 3691968, 5130909, 5515121, 9331441, 9546265

Offset

1,1

Comments

Also integers k such that A000217(k) == k (mod A066417(k)).

So far, only 33 belongs both to A232538 and A378414.

Links

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

Example

Antidivisors of 77 are 2, 3, 5, 9, 14, 17, 22, 31, 51 and their sum is 154.
Then 77*78/2 mod 154 = 3003 mod 154 = 77.

Maple

with(numtheory): P:=proc(q) local j, k, n, v; v:=[];
for n from 3 to q do k:=0; j:=n; while j mod 2<>1 do k:=k+1; j:=j/2; od;
if n*(n+1)/2 mod (sigma(2*n+1)+sigma(2*n-1)+sigma(n/2^k)*2^(k+1)-6*n-2)=n
then v:=[op(v), n]; fi; od; op(v); end: P(10^5);

Crossrefs

Cf. A000217, A066417, A232538, A378414.

Sequence in context: A138841 A248979 A246409 * A211837 A138863 A138866

Adjacent sequences: A378478 A378479 A378480 * A378482 A378483 A378484

Keyword

nonn,easy

Author

Paolo P. Lava, Nov 28 2024

Status

approved