A002953 Larger of unitary amicable pair.

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

Author

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

Keywords

• nonn
• nice

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

Crossrefs

Cf. A002952, A063991, A111904.

Programs

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 *)