1,1

J. Pe, On a Generalization of Perfect Numbers, J. Rec. Math., 31(3) (2002-2003), 168-172.

Proper divisors of 22 are {1,2,11}; f applied to these = {0, 1, 10}, which sum to 11 = f(223). Proper divisors of 223 are {1}; f applied to these = {0}, which sum to 0 = f(22). Hence 22, 223 is an f-amicable pair.

f[x_] := Floor[Abs[x*Sin[x]]]; d[x_] := Apply[ Plus, Map[ f, Divisors[ x] ] ] - f[ x]; m = Table[{x, y}, {x, 1, 1000}, {y, 1, 1000}]; Do[a = m[[i, j]]; If[ (a[[1]] < a[[2]]) && (f[a[[1]]] == d[a[[2]]]) && (f[a[[2]]] == d[a[[1]]]), Print[{i, j}]], {i, 1, 1000}, {j, 1, 1000}]

Cf. A066511, A066218.

Adjacent sequences: A066570 A066571 A066572 this_sequence A066574 A066575 A066576

Sequence in context: A125385 A126543 A008453 this_sequence A121087 A133719 A008948

nonn

Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Jan 07 2002