The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A077225 Starting with a(0)=1, smallest squarefree number k such that, for all a(m), m

%I

%S 1,3,15,17,233,291,577,723,1455,3615,8117,8835,9505,30833,128773,

%T 130827,239595,273435,426891,654135,676297,926117,145553,1662533,

%U 2389517,2762427,2820927,7994449,8098527,14319073,16766835,20506733,27606617

%N Starting with a(0)=1, smallest squarefree number k such that, for all a(m), m<n, k+a(m) is not squarefree.

%e 17 belongs to this sequence as 17+1, 17+3, 17+15 all are divisible by some square.

%o (PARI) v=vector(60):v=1:print1("1,"):for(n=2,60, for(k=1,10^15,if(issquarefree(k),s=0:for(l=1,n-1,if(issquarefree(k+v[l]),break):s=s+1)): if(s==n-1,print1(k","):v[n]=k:break)))

%Y Cf. A077224.

%K nonn

%O 0,2

%A _Amarnath Murthy_, Nov 03 2002

%E Edited by _Ralf Stephan_, Mar 25 2003

%E More terms from _Sam Alexander_, Dec 12 2003

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 28 04:43 EDT 2021. Contains 348313 sequences. (Running on oeis4.)