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%I #22 Apr 09 2020 09:57:06
%S 1,15,22,77
%N Nonprimes whose divisors are partition numbers.
%C By definition all terms are partition numbers.
%C Conjecture: no terms exist beyond 77. - _Jon E. Schoenfield_, Feb 05 2014
%e 15 is in the sequence because 15 is a nonprime number and the divisors of 15 are 1, 3, 5, 15, which are also partition numbers.
%t nmax = 1000;
%t pp = PartitionsP[Range[nmax]];
%t selQ[n_] := Module[{dd = Divisors[n]}, Intersection[pp, dd] == dd];
%t Select[Range[nmax], !PrimeQ[#] && selQ[#]&] (* _Jean-François Alcover_, Apr 09 2020 *)
%Y Cf. A000041, A018252, A038753, A236102, A236103, A236105, A236108, A236110.
%K nonn,more
%O 1,2
%A _Omar E. Pol_, Jan 22 2014
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