A143321 Positive integers k whose sum of distinct prime divisors divides k+1.

15, 20, 24, 35, 54, 95, 98, 104, 119, 135, 143, 144, 160, 189, 207, 209, 224, 287, 319, 323, 324, 351, 363, 375, 377, 384, 390, 459, 464, 527, 539, 559, 608, 779, 845, 864, 875, 899, 923, 989, 999, 1000, 1007, 1029, 1189, 1199, 1215, 1280, 1343, 1349, 1375

Offset

1,1

Links

David A. Corneth, Table of n, a(n) for n = 1..10000

Example

The distinct primes dividing 24 are 2 and 3, since 24 is factored as 2^3 *3^1. 2 + 3 = 5 is a divisor of 24 + 1 = 25. So 24 is a term of this sequence.

Maple

with(numtheory): a:= proc(n) local f: f:=factorset(n); if `mod`(n+1, add(i, i=f))=0 then n end if end proc: seq(a(n), n=2..1200); # Emeric Deutsch, Aug 14 2008

Mathematica

Select[Range[2, 1500], Divisible[#+1, Total[FactorInteger[#][[All, 1]]]]&] (* Harvey P. Dale, Aug 27 2022 *)

Prog

(PARI) is(n) = n > 1 && (n + 1) % vecsum(factor(n)[, 1]) == 0 \\ David A. Corneth, Mar 10 2019

Crossrefs

Cf. A008472, A089352, A143322.

Sequence in context: A316743 A014603 A070222 * A066860 A120159 A163602

Adjacent sequences: A143318 A143319 A143320 * A143322 A143323 A143324

Keyword

nonn

Author

Leroy Quet, Aug 07 2008

Extensions

More terms from Emeric Deutsch, Aug 14 2008

More terms from Max Alekseyev, Mar 10 2009

Status

approved