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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A137395 a(1)=1. a(n) = a(n-1) + (sum of the distinct primes that are <= n and don't divide a(n-1)). 1
1, 3, 5, 10, 13, 23, 40, 50, 60, 67, 95, 118, 157, 198, 223, 264, 306, 342, 395, 467, 544, 602, 693, 772, 870, 960, 1050, 1133, 1251, 1377, 1517, 1677, 1821, 1978, 2113, 2273, 2470, 2628, 2820, 3007, 3214, 3450, 3698, 3934, 4206, 4482, 4805, 5097, 5422, 5748 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

EXAMPLE

The primes <= 8 are 2,3,5,7. Of these, only 3 and 7 don't divide a(7)=40. So a(8) = a(7) + 3 + 7 = 50.

MAPLE

A137395 := proc(n) option remember ; local aprev, i, a, p; if n = 1 then RETURN(1) ; fi; aprev := A137395(n-1) ; a := aprev ; for i from 1 do p := ithprime(i) ; if p > n then break; fi ; if aprev mod p <> 0 then a := a+p ; fi ; od: a ; end: seq(A137395(n), n=1..100) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 23 2008

CROSSREFS

Sequence in context: A165718 A031878 A160792 * A001767 A048214 A195094

Adjacent sequences:  A137392 A137393 A137394 * A137396 A137397 A137398

KEYWORD

nonn

AUTHOR

Leroy Quet Apr 10 2008

EXTENSIONS

More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 23 2008

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 14 06:43 EST 2012. Contains 205575 sequences.