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

1,1

Comments

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

Links

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

Example

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

Prog

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

Crossrefs

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

Sequence in context: A095641 A306291 A055036 * A274357 A052476 A297912

Adjacent sequences: A358393 A358394 A358395 * A358397 A358398 A358399

Keyword

nonn

Author

Jianing Song, Nov 13 2022

Status

approved