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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A008366 Smallest prime factor is >= 17. 7
1, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Also the 17-rough numbers: positive integers that have no prime factors less than 17 [From Michael Porter (michael_b_porter(AT)yahoo.com), Oct 10 2009]

LINKS

Eric Weisstein's World of Mathematics, Rough Number

Index entries for sequences related to smooth numbers [From Michael Porter (michael_b_porter(AT)yahoo.com), Oct 10 2009]

FORMULA

Numbers n such that (sum(k^10, k= 1..n) mod n =0) and (sum(k^12, k=1..n) mod n =0),n>1. (Conjecture). [From Gary Detlefs, Dec 27 2011]

MAPLE

for i from 1 to 500 do if gcd(i, 30030) = 1 then print(i); fi; od;

MATHEMATICA

Select[ Range[ 300 ], GCD[ #1, 30030 ]==1& ]

PROG

(PARI) isA008366(n) = gcd(n, 30030)==1 [From Michael Porter (michael_b_porter(AT)yahoo.com), Oct 10 2009]

CROSSREFS

For k-rough numbers with other values of k, see A000027 A005408 A007310 A007775 A008364 A008365 A008366 A166061 A166063 [From Michael Porter (michael_b_porter(AT)yahoo.com), Oct 10 2009]

Sequence in context: A115849 A054484 A054796 * A126769 A092216 A180948

Adjacent sequences:  A008363 A008364 A008365 * A008367 A008368 A008369

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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 15 14:30 EST 2012. Contains 205814 sequences.