1,3

Rémy Sigrist, Table of n, a(n) for n = 1..10000

N. J. A. Sloane, Maple programs for A007916, A278028, A278029, A052409, A089723, A277564

FoldList[Boole[#2 != #1] #2 &, #] &@ Accumulate@ Array[Boole[And[# > 1, CoprimeQ @@ FactorInteger[#][[All, -1]]]] &, 81] (* Michael De Vlieger, Dec 18 2016 *)

Cf. A007916.

Sequence in context: A137218 A087819 A290820 * A066246 A198370 A173517

Adjacent sequences: A278026 A278027 A278028 * A278030 A278031 A278032

nonn

N. J. A. Sloane, Nov 10 2016

approved