A002953 Larger of unitary amicable pair. (Formerly M5389)

126, 1260, 22302, 40446, 49308, 64530, 73962, 168730, 223020, 286500, 242730, 429750, 365700, 548550, 618570, 827700, 739620, 827652, 932100, 1241550, 1099390, 1291050, 1292570, 1241478, 1398150, 1621500, 1669150, 1598470, 1654212

Offset

1,1

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

T. D. Noe, Table of n, a(n) for n = 1..7896 (from Pedersen's website)

Peter Hagis, Jr., Unitary amicable numbers, Math. Comp., 25 (1971), 915-918.

J. M. Pedersen, Known Unitary Amicable Pairs

J. O. M. Pedersen, Tables of Aliquot Cycles [Broken link]

J. O. M. Pedersen, Tables of Aliquot Cycles [Via Internet Archive Wayback-Machine]

J. O. M. Pedersen, Tables of Aliquot Cycles [Cached copy, pdf file only]

Ivars Peterson, Amicable Pairs, Divisors, and a New Record, January 30 2004.

Eric Weisstein's World of Mathematics, Unitary Amicable Pair

Mathematica

uDivisors[n_] := Select[Divisors[n], # < n && GCD[#, n/#] == 1 & ]; mate[n_] := If[m = Total[uDivisors[n]]; n == Total[uDivisors[m]], m, 0]; Reap[Do[If[n < (m = mate[n]), Print[m]; Sow[m]], {n, 2, 2000000}]][[2, 1]] (* Jean-François Alcover, Jun 12 2012 *)

Crossrefs

Cf. A002952, A063991, A111904.

Sequence in context: A154093 A172139 A194717 * A216588 A297657 A027805

Adjacent sequences: A002950 A002951 A002952 * A002954 A002955 A002956

Keyword

nonn,nice

Author

N. J. A. Sloane; extended Nov 24 2005

Status

approved