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Integers that reach the (1023, 512) cycle described in A234534, after iterations of numerator(sigma(n)/n) = A017665(n).
3

%I #5 Nov 03 2014 10:47:19

%S 81,106,121,133,148,160,162,170,189,211,212,214,237,297,301,313,314,

%T 320,340,352,361,378,381,394,409,410,428,438,442,474,502,512,535,583,

%U 605,609,621,627,645,647,648,657,680,691,692,704,709,710,717,736,742,748

%N Integers that reach the (1023, 512) cycle described in A234534, after iterations of numerator(sigma(n)/n) = A017665(n).

%o (PARI) finalc(x, v) = {while (!vecsearch(v, x), x = numerator(sigma(x)/x)); x;}

%o lista(nn, targ=512) = {v = [8, 127, 512, 29127]; for (i=2, nn, if (finalc(i, v) == targ, print1(i, ", ")););}

%Y Cf. A017665, A234534, A249611, A249612, A249614.

%K nonn

%O 1,1

%A _Michel Marcus_, Nov 02 2014