A173156 - OEIS

A173156

Numbers n such that max(tau(n),tau(n+1),tau(n+2),tau(n+3))- min(tau(n),tau(n+1),tau(n+2),tau(n+3)) = 1.

2, 20164, 155236, 293761, 293762, 643204, 1435204, 1444802, 5216653, 6120676, 8421601, 8421602, 14047501, 15194404, 15984004, 17606413, 19114383, 22829284, 25786083, 25989602, 35259843, 35259844, 36264484, 41499364, 42876301, 44382241, 50523662, 50523663

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..1000

EXAMPLE

For n = 20164, max(tau(20164),tau(20165),tau(20166),tau(20167)) - min(tau(20164),tau(20165),tau(20166),tau(20167)) = max(9,8,8,8) - min(9,8,8,8) = 1.

MAPLE

with(numtheory):for n from 200000 to 1500000 do; if max(tau(n), tau(n+1), tau(n+2), tau(n+3))- min(tau(n), tau(n+1), tau(n+2), tau(n+3))= 1 then print(n); else fi ; od;

MATHEMATICA

Position[Partition[DivisorSigma[0, Range[5053*10^4]], 4, 1], _?(Max[#]-Min[#] == 1&)]// Flatten (* Harvey P. Dale, Jan 23 2023 *)

CROSSREFS

Cf. A000005, A006558.

Sequence in context: A158344 A319383 A124364 * A214598 A346988 A339476

Adjacent sequences: A173153 A173154 A173155 * A173157 A173158 A173159

KEYWORD

nonn

AUTHOR

Michel Lagneau, Feb 11 2010

EXTENSIONS

a(13)-a(28) from Giovanni Resta, Jun 12 2016

STATUS

approved