This site is supported by donations to The OEIS Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A235700 a(n+1) = a(n) + (a(n) mod 5), a(1)=1. 4
 1, 2, 4, 8, 11, 12, 14, 18, 21, 22, 24, 28, 31, 32, 34, 38, 41, 42, 44, 48, 51, 52, 54, 58, 61, 62, 64, 68, 71, 72, 74, 78, 81, 82, 84, 88, 91, 92, 94, 98, 101, 102, 104, 108, 111, 112, 114, 118, 121, 122, 124, 128, 131, 132, 134, 138, 141, 142, 144, 148, 151, 152, 154, 158, 161, 162, 164, 168, 171, 172, 174, 178, 181, 182, 184, 188, 191 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Although the present sequence has not been thought of via "writing a(n) in base b", this could be seen as "base 5" version of A102039 (base 10) and A001651 (base 3), A047235 (base 6), A047350 (base 7) and A007612 (base 9). For 4 or 8 one would get a sequence constant from that (3rd resp. 4th) term on. LINKS Index entries for linear recurrences with constant coefficients, signature (2,-2,2,-1). FORMULA a(n) = 2^(n-1 mod 4) + 10*floor((n-1)/4). a(n) = (-10+(1+2*i)*(-i)^n+(1-2*i)*i^n+10*n)/4 where i=sqrt(-1). a(n) = 2*a(n-1)-2*a(n-2)+2*a(n-3)-a(n-4). G.f.: x*(2*x^3+2*x^2+1) / ((x-1)^2*(x^2+1)). - Colin Barker, Jan 16 2014 PROG (PARI) is_A235700(n) = bittest(278, n%10) \\ 278=2^1+2^2+2^4+2^8 (PARI) A235700 = n -> 2^((n-1)%4)+(n-1)\4*10 (PARI) print1(a=1); for(i=1, 99, print1(", "a+=a%5)) (PARI) Vec(x*(2*x^3+2*x^2+1)/((x-1)^2*(x^2+1)) + O(x^100)) \\ Colin Barker, Jan 16 2014 CROSSREFS Sequence in context: A256980 A014425 A028889 * A174781 A028846 A274924 Adjacent sequences:  A235697 A235698 A235699 * A235701 A235702 A235703 KEYWORD nonn,easy AUTHOR M. F. Hasler, Jan 14 2014 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.

Last modified October 22 07:48 EDT 2019. Contains 328315 sequences. (Running on oeis4.)