A227387 Numbers n such that sigma(n)*7 < sigma(n-1) + sigma(n+1).

41902660799, 41902660801, 48886437599, 53542288799, 55870214401, 62853991199, 73329656401, 80313433201, 96376119841, 97772875199, 97772875201, 101264763599, 107084577599, 107221514401, 118356638399, 118356638401, 125707982401, 128501493121, 135019684799

Offset

1,1

Comments

Conjecture: the sequence is infinite.

Links

Giovanni Resta, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A000203, A072828.

Sequence in context: A172721 A259350 A237495 * A179227 A003940 A003933

Adjacent sequences: A227384 A227385 A227386 * A227388 A227389 A227390

Keyword

nonn

Author

Alex Ratushnyak, Jul 09 2013

Extensions

a(7)-a(19) from Giovanni Resta, Jul 15 2013

Status

approved