A038362 Two different numbers a, b which satisfy sigma(a)=sigma(b)=(a+b)^3/(a^2+b^2) are called a rational amicable pair; sequence gives a numbers.

26403469440047700, 7664549986025275200, 31637331117119006822400, 8100083754075263764070400, 129602081655678458639155200, 132712784683164075505282252800

Offset

1,1

Comments

These are just the known values. There is no proof that this sequence is correct (in the usual sense that there are no other terms below the last term shown). - N. J. A. Sloane, Nov 07 2006

Factorization: 2^(n-1)*M(n)*3*5^2*13*31*139*277*3877*11*19 where M(n) is Mersenne Prime, n=3 or 5<n.

Links

Table of n, a(n) for n=1..6.

Eric Weisstein's World of Mathematics, Rational Amicable Pair.

Crossrefs

Cf. A038363.

Sequence in context: A080127 A003941 A003934 * A038363 A204189 A317163

Adjacent sequences: A038359 A038360 A038361 * A038363 A038364 A038365

Keyword

nonn,more

Author

Yasutoshi Kohmoto

Status

approved