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 A143322 A positive integer n is included if the sum of the distinct prime divisors of n divides n-1. 1
 6, 21, 28, 36, 50, 96, 99, 216, 225, 301, 325, 352, 400, 441, 486, 495, 496, 576, 630, 676, 697, 784, 847, 925, 1225, 1296, 1333, 1521, 1536, 1587, 1695, 1701, 1792, 1909, 2025, 2041, 2133, 2145, 2500, 2601, 2624, 2916, 2926, 3025, 3200, 3220, 3276, 3456 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE The distinct primes dividing 28 are 2 and 7, since 28 is factored as 2^2 *7^1. 2+7=9 is a divisor of 28-1 = 27. So 28 is included in this sequence. MAPLE with(numtheory): a:=proc(n) local f: f:= factorset(n): if `mod`(n-1, add(f[i], i=1..nops(f)))=0 then n else end if end proc: seq(a(n), n=2..4000); [From Emeric Deutsch, Aug 16 2008] MATHEMATICA Select[Range[2, 5000], Divisible[#-1, Total[Transpose[FactorInteger[#]][[1]]]]&] (* Harvey P. Dale, Aug 03 2014 *) CROSSREFS Cf. A008472, A089352, A143321. Sequence in context: A020880 A046467 A132184 * A246544 A034897 A287165 Adjacent sequences:  A143319 A143320 A143321 * A143323 A143324 A143325 KEYWORD nonn AUTHOR Leroy Quet, Aug 07 2008 EXTENSIONS Extended by Emeric Deutsch, Aug 16 2008 STATUS approved

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