%I #4 Sep 07 2018 04:44:22

%S 1,2,3,5,7,6,13,10,19,14,29,15,37,26,21,34,53,33,61,35,39,58,79,30,89,

%T 74,57,65,107,42,113,85,87,106,91,66,151,122,111,70,173,78,181,145,

%U 129,158,199,102,223,161,159,185,239,114,203,130,183,214,271,105

%N Minimum shifted Heinz number of a strict factorization of n into factors > 1.

%C The shifted Heinz number of a factorization (y_1, ..., y_k) is prime(y_1 - 1) * ... * prime(y_k - 1).

%e The strict factorizations of 60 are (2*3*10), (2*5*6), (2*30), (3*4*5), (3*20), (4*15), (5*12), (6*10), (60), with shifted Heinz numbers 138, 154, 218, 105, 201, 215, 217, 253, 277 respectively, so a(60) = 105.

%t facs[n_]:=If[n<=1,{{}},Join@@Table[(Prepend[#1,d]&)/@Select[facs[n/d],Min@@#1>=d&],{d,Rest[Divisors[n]]}]];

%t Table[Min[Times@@Prime/@(#-1)&/@Select[facs[n],UnsameQ@@#&]],{n,100}]

%Y Cf. A001055, A007716, A045778, A056239, A080688, A162247, A215366, A246868, A318871, A318953.

%K nonn

%O 1,2

%A _Gus Wiseman_, Sep 05 2018