OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
MATHEMATICA
f[n_]:=Plus@@Last/@FactorInteger[n]; lst={}; lst={}; Do[If[f[n]==f[n+1]==f[n+2], AppendTo[lst, n]], {n, 0, 7!}]; lst (* Vladimir Joseph Stephan Orlovsky, May 12 2010 *)
pd2Q[n_]:=PrimeOmega[n]==PrimeOmega[n+1]==PrimeOmega[n+2]; Select[Range[1700], pd2Q] (* Harvey P. Dale, Apr 19 2011 *)
SequencePosition[PrimeOmega[Range[1700]], {x_, x_, x_}][[;; , 1]] (* Harvey P. Dale, Mar 08 2023 *)
PROG
(PARI) is(n)=my(t=bigomega(n)); bigomega(n+1)==t && bigomega(n+2)==t \\ Charles R Greathouse IV, Sep 14 2015
(PARI) list(lim)=my(v=List(), a=1, b=1, c); forfactored(n=4, lim\1+2, c=bigomega(n); if(a==b&&a==c, listput(v, n[1]-2)); a=b; b=c); Vec(v) \\ Charles R Greathouse IV, May 07 2020
CROSSREFS
Numbers m through m+k have the same number of prime divisors (with multiplicity): A045920 (k=1), this sequence (k=2), A045940 (k=3), A045941 (k=4), A045942 (k=5), A123103 (k=6), A123201 (k=7), A358017 (k=8), A358018 (k=9), A358019 (k=10).
A056809 is a subsequence.
Cf. A006073. - Harvey P. Dale, Apr 19 2011
KEYWORD
nonn,easy
AUTHOR
STATUS
approved