A082800 Smallest multiple of 4 beginning with n.

12, 20, 32, 4, 52, 60, 72, 8, 92, 100, 112, 12, 132, 140, 152, 16, 172, 180, 192, 20, 212, 220, 232, 24, 252, 260, 272, 28, 292, 300, 312, 32, 332, 340, 352, 36, 372, 380, 392, 40, 412, 420, 432, 44, 452, 460, 472, 48, 492, 500, 512, 52, 532, 540, 552, 56

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (0,0,0,2,0,0,0,-1).

Formula

From Colin Barker, Mar 23 2017: (Start)

G.f.: 4*x*(3 + 5*x + 8*x^2 + x^3 + 7*x^4 + 5*x^5 + 2*x^6) / ((1 - x)^2*(1 + x)^2*(1 + x^2)^2).

a(n) = 2*a(n-4) - a(n-8) for n>8.

(End)

Mathematica

Table[If[Mod[n, 4]==0, n, If[Mod[10 n, 4]==0, 10 n, 10 n + 4 - Mod[10 n, 4]]], {n, 56}] (* Ray Chandler, Feb 09 2014 *)

Prog

(PARI) Vec(4*x*(3 + 5*x + 8*x^2 + x^3 + 7*x^4 + 5*x^5 + 2*x^6) / ((1 - x)^2*(1 + x)^2*(1 + x^2)^2) + O(x^60)) \\ Colin Barker, Mar 23 2017

Crossrefs

Cf. A082799, A082801, A082802, A082803, A082804.

Sequence in context: A109547 A334418 A269453 * A026041 A299028 A082296

Adjacent sequences: A082797 A082798 A082799 * A082801 A082802 A082803

Keyword

nonn,base,easy

Author

Amarnath Murthy, Apr 20 2003

Extensions

Extended by Ray Chandler, Feb 09 2014

Typo in Mathematica program fixed by Vincenzo Librandi, Feb 10 2014

Status

approved