login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A076144 Largest squarefree m <= sfn(n) such that m*sfn(n) is also squarefree, where sfn(n) is the n-th squarefree number. 1
1, 1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 26, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 46, 47, 51, 53, 55, 57, 58, 59, 61, 62, 65, 66, 67, 69, 70, 71, 73, 74, 77, 78, 79, 82, 83, 85, 86, 87, 89, 91, 93, 94, 95, 97, 101, 102, 103, 105, 106, 107, 109 (list; graph; refs; listen; history; internal format)
OFFSET

1,3

COMMENTS

gcd(a(n),spf(n))=1;

a(n+1)=sfn(n) for n<106, but a(107)=173=sfn(105), as sfn(107)*sfn(106)=177*174=(3*59)*(2*3*29) is not squarefree.

CROSSREFS

a(i+1) = A005117(i) only for 1<=i<106. Cf. A077395.

Sequence in context: A064052 A064594 A193304 * A005117 A144338 A077377

Adjacent sequences:  A076141 A076142 A076143 * A076145 A076146 A076147

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 30 2002

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 03:45 EST 2012. Contains 205978 sequences.