A290469 Numbers x such that x = Sum_{i=1..k} (x mod d_(x+i)) for some k, where d_(x+i) is the aliquot parts of (x+i).

5, 10, 11, 14, 30, 145, 195, 367, 375, 471, 1695, 2523, 9807, 21249, 30847, 437744, 2075647, 2346495, 8341503, 14223687, 33452031, 15085100835

Offset

1,1

Comments

Values of k for the listed terms are 3, 4, 1, 2, 3, 2, 1, 1, 2, 2, 1, 2, 2, 2, 1, 1, 1, 2.

Links

Table of n, a(n) for n=1..22.

Example

For 5 the value of k is 3. Aliquot parts of 6, 7 and 8 are: [1, 2, 3], [1], [1, 2, 4]. Residues are 0 + 1 + 2 + 0 + 0 + 1 + 1 that sum up to 5.

Maple

with(numtheory): P:=proc(q) local a, b, j, k, n; for n from 3 to q do
a:=0; k:=0; while a<n do k:=k+1; b:=sort([op(divisors(n+k))]);
a:=a+add(n mod b[j], j=1..nops(b)-1); od;
if a=n then print(n); fi; od; end: P(10^9);

Crossrefs

Cf. A286873, A290468.

Sequence in context: A038030 A094016 A116033 * A140507 A297255 A296699

Adjacent sequences: A290466 A290467 A290468 * A290470 A290471 A290472

Keyword

nonn,more

Author

Paolo P. Lava, Aug 03 2017

Extensions

a(19)-a(22) from Giovanni Resta, Aug 04 2017

Status

approved