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A365619 a(n) is the least integer k such that A366110(k) = n, or 0 if there is no such k.

%I A365619 #14 Nov 04 2023 14:01:23
%S A365619 0,0,0,0,0,454,0,13,0,0,0,19,0,16,0,17,15,22,6,0,0,0,0,0,0,0,0,23,0,
%T A365619 396,0,0,0,46,0,148,40,0,8,0,0,652,0,15980,0,0,0,25,0,0,0,0,0,50,0,0,
%U A365619 0,0,0,136,0,0,0,27,0,64,0,0,0,100,0,29,21,0,0,0,0,15574,0,0,0,0,0,346
%N A365619 a(n) is the least integer k such that A366110(k) = n, or 0 if there is no such k.
%C A365619 The nonzero values are sure, but the zeros are conjectured.
%C A365619 Search was conducted up to 10^5.
%H A365619 Michel Marcus, <a href="/A365619/a365619.txt">Table of n, a(n) for n = 1..10000</a>
%o A365619 (PARI) lista(ns) = my(nn=100); my(vs = vector(ns, k, [])); forcomposite (i=1, (ns/2)^2, my(x=sigma(i)-i); if (x <= ns, if (#vs[x] <= 1, vs[x] = concat(vs[x], i), vs[x][2] = i));); my(v = vector(nn)); for (i=1, #vs, if (#vs[i] > 1, my(d = vecmax(vs[i])-vecmin(vs[i])); if ((d<=nn) && (!v[d] || (v[d]>i)), v[d] = i););); v;
%o A365619 lista(2*10^4)
%Y A365619 Cf. A152454, A366110.
%K A365619 nonn
%O A365619 1,6
%A A365619 _Michel Marcus_, Nov 02 2023