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A067741
Integers y such that for some integer x we have uphi(x) = uphi(y) = x-y, where uphi(n) = A047994(n) is the unitary totient function: If n = Product p_i^e_i, uphi(n) = Product (p_i^e_i - 1).
5
1, 36, 294, 504, 1830, 2142, 3042, 4746, 7380, 7782, 8100, 15642, 22734, 38610, 47736, 77166, 103320, 107114, 112110, 134070, 153270, 189434, 189954, 234024, 239850, 243438, 275834, 287790, 296646, 305910, 314262, 345042, 361350, 410424
OFFSET
1,2
LINKS
MATHEMATICA
uphi[n_] := Times@@(Power@@#-1&/@FactorInteger[n]); For[y=1, True, y++, If[uphi[x=y+(u=uphi[y])]==u, Print[{y, x}]]]
CROSSREFS
Sequence in context: A017462 A226836 A218647 * A374503 A185096 A073972
KEYWORD
nonn
EXTENSIONS
Edited by Dean Hickerson, Mar 07 2002
Offset corrected by Donovan Johnson, May 04 2013
STATUS
approved