A216606 Decimal expansion of 360/7.

5, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7, 1, 4, 2, 8, 5, 7

Offset: 2

Author

Paul Curtz, Sep 10 2012

Keywords

• nonn
• cons
• less
• easy

Comments

A020806 preceded by a 5.

Number of degrees in the exterior angle of an equilateral heptagon. Since 1969, used in many (orbiform or Reuleaux) heptagonal coins. Zambia has a natural heptagonal coin. Brazil and Costa Rica have a coin with the natural heptagon inscribed in the coin's disk.

Examples

			51.42857...
		

Links

• World of Coins, An Alphabet of Heptagons: Seven-sided Coins.
• Index entries for linear recurrences with constant coefficients, signature (1,0,-1,1).

Crossrefs

Cf. A019695, A020806, A021018, A060708, A068028, A178817, A178818.

Programs

Maple

Digits:=100: evalf(360/7); # Wesley Ivan Hurt, Jun 28 2016

Mathematica

Flatten[RealDigits[360/7, 10, 100]] (* Wesley Ivan Hurt, Jun 28 2016 *)

PARI

360/7. \\ Charles R Greathouse IV, Sep 12 2012

Formula

a(n) = 50 + 10*A020806(n).

After 5, of period 6: repeat [1, 4, 2, 8, 5, 7].

From Wesley Ivan Hurt, Jun 28 2016: (Start)

G.f.: x^3*(5-4*x+3*x^2+3*x^3+2*x^4) / (1-x+x^3-x^4).

a(n) = 9/2 + 11*cos(n*Pi)/6 + 5*cos(n*Pi/3)/3 + sqrt(3)*sin(n*Pi/3), n>2.

a(n) = a(n-1) - a(n-3) + a(n-4) for n>6, a(n) = a(n-6) for n>8. (End)