A358396 Even numbers k such that sigma(k) + sigma(k+2) < 2*sigma(k+1); even terms in A053229.

104, 134, 164, 314, 404, 494, 524, 554, 566, 584, 674, 692, 734, 764, 854, 944, 974, 1124, 1154, 1196, 1214, 1304, 1322, 1364, 1394, 1484, 1574, 1682, 1724, 1754, 1784, 1814, 1826, 1844, 1994, 2024, 2144, 2204, 2384, 2414, 2456, 2474, 2564, 2624, 2654, 2804, 2834, 3002

Offset: 1

Author

Jianing Song, Nov 13 2022

Keywords

• nonn

Comments

Even numbers k such that A053223(k) < 0.

Examples

			104 is a term since sigma(105) = 192 is greater than the average of sigma(104) = 210 and sigma(106) = 162.
		

Links

• Jianing Song, Table of n, a(n) for n = 1..20000

Crossrefs

Cf. A053229, A053223, A000203 (sigma), A358395.

Programs

PARI

isA358396(n) = !(n%2) && (sigma(n) + sigma(n+2) < 2*sigma(n+1))