|
| |
|
|
A032793
|
|
Numbers that are congruent to {1, 2, 4} mod 5.
|
|
22
| |
|
|
1, 2, 4, 6, 7, 9, 11, 12, 14, 16, 17, 19, 21, 22, 24, 26, 27, 29, 31, 32, 34, 36, 37, 39, 41, 42, 44, 46, 47, 49, 51, 52, 54, 56, 57, 59, 61, 62, 64, 66, 67, 69, 71, 72, 74, 76, 77, 79, 81, 82, 84, 86, 87, 89, 91, 92, 94, 96, 97, 99, 101, 102, 104, 106, 107, 109
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (1,0,1,-1).
|
|
|
FORMULA
| a(n) = +1*a(n-1) +1*a(n-3) -1*a(n-4).
a(n)=-1+Sum_{k=1..n}{(1/9)*(2*(k mod 3)+8*[(k+1) mod 3]+5*[(k+2) mod 3]}, with n>=1 [From Paolo P. Lava (paoloplava(AT)gmail.com), Sep 03 2010]
a(n)=floor((5*n-2)/3). [From Gary Detlefs (gdetlefs(AT)aol.com), May 14 2011]
G.f. x*(1+x+2*x^2+x^3) / ( (1+x+x^2)*(x-1)^2 ). - R. J. Mathar, Oct 08 2011
|
|
|
MATHEMATICA
| Select[Range[0, 200], MemberQ[{1, 2, 4}, Mod[#, 5]] &] (* From Vladimir Joseph Stephan Orlovsky, Feb 11 2012 *)
|
|
|
PROG
| (MAGMA)[ n: n in [0..120] | n mod 5 in {1, 2, 4} ]; [From Vincenzo Librandi, Dec 29 2010]
(PARI) a(n)=n\3*5+[-1, 1, 2][n%3+1] \\ Charles R Greathouse IV, Jan 18 2012
|
|
|
CROSSREFS
| Cf. A032794, A032795.
Sequence in context: A186151 A184732 A039009 * A195127 A083088 A080755
Adjacent sequences: A032790 A032791 A032792 * A032794 A032795 A032796
|
|
|
KEYWORD
| nonn,easy,changed
|
|
|
AUTHOR
| Patrick De Geest (pdg(AT)worldofnumbers.com), May 15, 1998.
|
|
|
EXTENSIONS
| Better description from Michael Somos, Jun 08 2000.
|
| |
|
|
