login
A133043
Number of segments needed to draw the spiral of equilateral triangles with side lengths which follow the Padovan sequence.
1
3, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65
OFFSET
1,1
FORMULA
a(1)=3: a(2)=5: a(3)=6; for n>3, a(n)=n+4.
MATHEMATICA
LinearRecurrence[{2, -1}, {3, 5, 6, 8, 9}, 70] (* Harvey P. Dale, Dec 21 2018 *)
PROG
(PARI) a(n)=if(n>3, n+4, [3, 5, 6][n]) \\ Charles R Greathouse IV, Oct 27 2011
CROSSREFS
Cf. Padovan sequence: A000931.
Sequence in context: A201906 A267158 A161529 * A094058 A288134 A175966
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Nov 04 2007, Nov 05 2007
STATUS
approved