A069122 Numbers k such that the squarefree part of k is greater than the squarefree part of (k+1).

3, 7, 8, 11, 15, 17, 19, 23, 24, 26, 31, 35, 39, 43, 44, 47, 48, 51, 53, 55, 59, 62, 63, 67, 71, 74, 79, 80, 83, 87, 89, 91, 95, 97, 99, 103, 107, 111, 115, 116, 119, 120, 123, 124, 127, 131, 134, 139, 143, 146, 149, 151, 152, 155, 159, 161, 163, 167, 168, 170, 174

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

f[p_, e_] := If[OddQ[e], p, 1]; sqf[n_] := Times @@ (f @@@ FactorInteger[n]);  Select[Range[200], sqf[#] > sqf[# + 1] &] (* Amiram Eldar, Apr 02 2020 *)

Prog

(PARI) for(n=1, 220, if(core(n)>core(n+1), print1(n, ", ")))

Crossrefs

Cf. A007913.

Sequence in context: A194470 A078466 A047528 * A278519 A007970 A255342

Adjacent sequences: A069119 A069120 A069121 * A069123 A069124 A069125

Keyword

easy,nonn

Author

Benoit Cloitre, Apr 07 2002

Status

approved