|
| |
|
|
A047219
|
|
Numbers that are congruent to {1, 3} mod 5.
|
|
27
| |
|
|
1, 3, 6, 8, 11, 13, 16, 18, 21, 23, 26, 28, 31, 33, 36, 38, 41, 43, 46, 48, 51, 53, 56, 58, 61, 63, 66, 68, 71, 73, 76, 78, 81, 83, 86, 88, 91, 93, 96, 98, 101, 103, 106, 108, 111, 113, 116, 118, 121, 123, 126, 128, 131, 133, 136, 138, 141, 143, 146, 148
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (1,1,-1).
|
|
|
FORMULA
| a(n) = floor((5n-3)/2). - Santi Spadaro (spados(AT)katamail.com), Jul 24 2001, corrected by Gary Detlefs, Oct 28 2011.
Row sums of triangle A131900 - Gary W. Adamson (qntmpkt(AT)yahoo.com), Jul 25 2007
a(n)=5*n-a(n-1)-6 (with a(1)=1) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 05 2010]
a(n)=(1/4)*[ -7-(-1)^n+10*n], with n>=1 [From Paolo P. Lava (paoloplava(AT)gmail.com), Sep 03 2010]
G.f. x*(1+2*x+2*x^2) / ( (1+x)*(x-1)^2 ). - R. J. Mathar, Oct 07 2011
|
|
|
MATHEMATICA
| Select[Range[0, 200], MemberQ[{1, 3}, Mod[#, 5]] &] (* From Vladimir Joseph Stephan Orlovsky, Feb 12 2012 *)
|
|
|
PROG
| (PARI) a(n)=(5*n-3)\2 \\ Charles R Greathouse IV, Oct 28 2011
|
|
|
CROSSREFS
| Cf. A000566, A131900.
Sequence in context: A189679 A190229 A190085 * A139477 A122437 A090848
Adjacent sequences: A047216 A047217 A047218 * A047220 A047221 A047222
|
|
|
KEYWORD
| nonn,easy,changed
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
| |
|
|
