A244666 Numbers n such that floor(antisigma(n) / sigma(n)) = floor(antisigma(n+1) / sigma(n+1)).

1, 2, 3, 9, 21, 33, 81, 261, 897, 1334, 1364, 2974, 4364, 14282, 26937, 46593, 64665, 74918, 79833, 92685, 145215, 147454, 161001, 162602, 166934, 289454, 347738, 383594, 422073, 430137, 440013, 443402, 445874, 621027, 649154, 655005, 1174305, 1187361, 1670955

Offset: 1

Author

Jaroslav Krizek, Jul 08 2014

Keywords

• nonn

Comments

Also numbers n such that floor((n*(n+1)/2) / sigma(n)) = floor(((n+1)*(n+2)/2) / sigma(n+1)).

Numbers n such that A244327(n) = A244327(n+1).

Numbers n such that A244329(n) = A244329(n+1).

Links

• Jaroslav Krizek, Table of n, a(n) for n = 1..39

Crossrefs

Cf. A000203, A000217, A024816, A046022, A244327, A244328, A244329.

Programs

Magma

[n: n in [1..10^6] | Floor((n*(n+1)div 2) div (SumOfDivisors(n))) eq Floor(((n+1)*(n+2)div 2) div (SumOfDivisors(n+1)))]