A102042 a(n) = a(n-1) + last digit of a(n-1), starting at 9.

9, 18, 26, 32, 34, 38, 46, 52, 54, 58, 66, 72, 74, 78, 86, 92, 94, 98, 106, 112, 114, 118, 126, 132, 134, 138, 146, 152, 154, 158, 166, 172, 174, 178, 186, 192, 194, 198, 206, 212, 214, 218, 226, 232, 234, 238, 246, 252, 254, 258, 266, 272, 274, 278, 286, 292

Offset

1,1

Comments

After 1 or 2 initial terms, respectively, the same as A102041. - R. J. Mathar, Aug 30 2008

Links

Colin Barker, Table of n, a(n) for n = 1..1000

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

Formula

G.f.: x*(-5*x^4-2*x^3+8*x^2+9)/((x-1)^2*(x^2+1)). - Charles R Greathouse IV, Oct 04 2011

a(n) = 10+(1-i/2)*(-i)^n+(1+i/2)*i^n+5*n for n>1, where i = sqrt(-1). - Colin Barker, Oct 19 2015

Example

34 + 4 = 38, 38 + 8 = 46.

Mathematica

NestList[#+Last[IntegerDigits[#]]&, 9, 60] (* Harvey P. Dale, Sep 19 2011 *)

Prog

(PARI) Vec(x*(-5*x^4-2*x^3+8*x^2+9)/((x-1)^2*(x^2+1))+O(x^99)) \\ Charles R Greathouse IV, Oct 04 2011

Crossrefs

Sequence in context: A371083 A328252 A227279 * A332551 A121282 A205716

Adjacent sequences: A102039 A102040 A102041 * A102043 A102044 A102045

Keyword

easy,nonn,base

Author

Samantha Stones (devilsdaughter2000(AT)hotmail.com), Dec 25 2004

Extensions

Formula adjusted for offset 1.

Status

approved