A242484 Numbers n such that antisigma(n) mod n = 0, where antisigma(n) = A024816(n) = sum of numbers less than n which do not divide n.

1, 2, 24, 4320, 4680, 26208, 8910720, 17428320, 20427264, 91963648, 197064960, 8583644160, 10200236032, 21857648640, 57575890944, 57629644800, 206166804480, 17116004505600, 1416963251404800, 15338300494970880

Offset

1,2

Comments

Numbers n such that antisigma(n) mod n = A229110(n) = 0.

If there are any odd multiply-perfect numbers, they are members of this sequence.

If there is no odd multiply-perfect number, then a(n) = A159907(n-1) for n >= 2.

Links

Table of n, a(n) for n=1..20.

Example

24 is in sequence because antisigma(24) mod 24 = 240 mod 24 = 0.

Prog

(Magma) [n: n in [1..1000000] | 0 eq ((n*(n+1))div 2 - SumOfDivisors(n)) mod n]

Crossrefs

Cf. A242480, A242481, A242482, A242483, A242485, A242486.

Sequence in context: A059332 A000794 A159907 * A088912 A342573 A203465

Adjacent sequences: A242481 A242482 A242483 * A242485 A242486 A242487

Keyword

nonn

Author

Jaroslav Krizek, May 16 2014

Status

approved