login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A102042 a(n) = a(n-1) + last digit of a(n-1), starting at 9. 1
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 (list; graph; refs; listen; history; text; internal format)
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.

MAPLE

P:=proc(i) local a, b, c, n; a:=9; print(a); for n from 0 by 1 to i do a:=a+a-10*trunc(a/10) ; print(a); od; end: P(100); # Paolo P. Lava, Sep 26 2008

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: A195268 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

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 20 04:53 EST 2021. Contains 340301 sequences. (Running on oeis4.)