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A035322 Sum of composite divisors of n that are less than n and are not primes nor prime powers. 4

%I #11 Jan 09 2019 19:07:02

%S 0,0,0,0,0,0,0,0,0,0,0,6,0,0,0,0,0,6,0,10,0,0,0,18,0,0,0,14,0,31,0,0,

%T 0,0,0,36,0,0,0,30,0,41,0,22,15,0,0,42,0,10,0,26,0,24,0,42,0,0,0,93,0,

%U 0,21,0,0,61,0,34,0,59,0,96,0,0,15,38,0,71,0,70,0,0,0,123,0,0,0,66,0

%N Sum of composite divisors of n that are less than n and are not primes nor prime powers.

%H Harvey P. Dale, <a href="/A035322/b035322.txt">Table of n, a(n) for n = 1..1000</a>

%t Table[ Plus @@ Select[ Divisors[ n ], (Length[ FactorInteger[ # ] ]>1 && #<n )& ], {n, 1, 100} ]

%t scd[n_]:=Total[Select[Most[Divisors[n]],CompositeQ[#]&&!PrimePowerQ[#]&]]; Array[scd,90] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jan 09 2019 *)

%Y Cf. A000203, A035321, A023891, A060278.

%K nonn

%O 1,12

%A _N. J. A. Sloane_.

%E Description corrected by _Jack Brennen_, Mar 28 2001

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Last modified March 29 21:18 EDT 2024. Contains 371281 sequences. (Running on oeis4.)