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) .[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
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
More terms from Erich Friedman.
STATUS
approved