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Rare primitive pseudoperfect numbers: primitive pseudoperfect numbers k such that k == 2 or 10 (mod 12).
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%I #7 Nov 02 2019 06:53:28

%S 350,490,550,650,770,910,1190,1330,1430,1610,1870,2002,2030,2090,2170,

%T 2210,2470,2530,2590,2870,2990,3010,3190,3230,3290,3410,3710,3770,

%U 4070,4130,4270,4510,4690,4730,4970

%N Rare primitive pseudoperfect numbers: primitive pseudoperfect numbers k such that k == 2 or 10 (mod 12).

%H Amiram Eldar, <a href="/A109762/b109762.txt">Table of n, a(n) for n = 1..3000</a>

%p PSP := proc(l::list) local x, R, S, P, L; S:=sort(l); R:=[]; P:=S; for x in S do if not(x in R) then L:=selectremove(proc(z) not(z=x) and z mod x = 0 end, P); R:=[op(R),op(L[1])]; P:=L[2]; fi; od; return P; end: PSP(RSP); # RSP is sequence of rare pseudoperfect numbers

%Y Cf. A006036, A109761.

%K nonn

%O 1,1

%A _Walter Kehowski_, Aug 13 2005