OFFSET
1,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..8999
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,10,-10).
FORMULA
From Chai Wah Wu, Sep 15 2020: (Start)
a(n) = a(n-1) + 10*a(n-9) - 10*a(n-10) for n > 17.
G.f.: 2*x*(45*x^16 - 45*x^15 + 45*x^14 - 45*x^13 + 45*x^12 - 45*x^11 + 45*x^10 - 45*x^9 + 5*x^8 - 4*x^7 + 5*x^6 - 4*x^5 + 5*x^4 - 4*x^3 + 5*x^2 - 4*x + 5)/((x - 1)*(10*x^9 - 1)). (End)
a(n) = 2 * A077491(n). - Alois P. Heinz, Sep 15 2020
MATHEMATICA
t={}; Do[i=2; While[Total[IntegerDigits[i]]!=n, i=i+2]; AppendTo[t, i], {n, 48}]; t (* Jayanta Basu, May 18 2013 *)
PROG
(PARI) a(n) = {my(k = 2); while(sumdigits(k) != n, k+=2); k; } \\ Michel Marcus, Mar 18 2016
CROSSREFS
KEYWORD
base,nonn,easy
AUTHOR
Amarnath Murthy, Apr 01 2002
EXTENSIONS
More terms from Ray Chandler, Jul 28 2003
STATUS
approved