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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A045802 2-ish numbers (end in 03, 21, 29, 47). 1
3, 21, 29, 47, 103, 121, 129, 147, 203, 221, 229, 247, 303, 321, 329, 347, 403, 421, 429, 447, 503, 521, 529, 547, 603, 621, 629, 647, 703, 721, 729, 747, 803, 821, 829, 847, 903, 921, 929, 947, 1003, 1021, 1029, 1047, 1103, 1121, 1129, 1147, 1203, 1221 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (1,0,0,1,-1).

FORMULA

G.f.: x*(3+18*x+8*x^2+18*x^3+53*x^4)/(1-x-x^4+x^5). - Colin Barker, Jan 23 2012

a(n) = (50*n-24*i^(n*(n+1))-7*(-1)^n-75)/2, where i=sqrt(-1). - Bruno Berselli, Feb 23 2012

a(1)=3, a(2)=21, a(3)=29, a(4)=47, a(5)=103, a(n)=a(n-1)+a(n-4)-a(n-5) [From Harvey P. Dale, May 05 2012]

MATHEMATICA

Join[{3}, Select[Range[10, 1300], MemberQ[{{0, 3}, {2, 1}, {2, 9}, {4, 7}}, Take[ IntegerDigits[#], -2]]&]] (* or *) LinearRecurrence[{1, 0, 0, 1, -1}, {3, 21, 29, 47, 103}, 50](* Harvey P. Dale, May 05 2012 *)

PROG

(Haskell)

import Data.List (findIndices)

a045802 n = a045802_list !! (n-1)

a045802_list = findIndices (`elem` [3, 21, 29, 47]) $ cycle [0..99]

-- Reinhard Zumkeller, Jan 23 2012

CROSSREFS

Cf. A045800-A045809, A045572, A045797, A045798.

Sequence in context: A062219 A091103 A292310 * A006133 A317860 A039766

Adjacent sequences:  A045799 A045800 A045801 * A045803 A045804 A045805

KEYWORD

nonn,base,easy

AUTHOR

J. H. Conway.

EXTENSIONS

More terms from Erich Friedman.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 23 12:43 EDT 2019. Contains 321430 sequences. (Running on oeis4.)