A067827 Even numbers k such that k/2 is nonprime and sigma(k+1) > sigma(k).

2, 404, 494, 524, 692, 764, 854, 944, 1034, 1124, 1394, 1682, 1784, 1826, 1844, 2114, 2204, 2294, 2414, 2534, 2564, 2714, 2774, 2804, 2834, 2924, 3002, 3014, 3044, 3074, 3266, 3284, 3374, 3434, 3464, 3644, 3674, 3794, 3842, 3854, 3884, 3914, 3926, 4094

Offset: 1

Author

Benoit Cloitre, Feb 08 2002

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000203, A053224.

Programs

Mathematica

Select[Range[2, 4000, 2], !PrimeQ[#/2] && DivisorSigma[1, # + 1] > DivisorSigma[1, #] &] (* Amiram Eldar, Apr 29 2022 *)