A077495 a(n) = smallest k such that the digit sum of 8k is n.
0, 125, 25, 15, 5, 4, 3, 2, 1, 9, 8, 7, 6, 23, 22, 12, 11, 37, 36, 62, 61, 87, 86, 112, 111, 236, 361, 486, 611, 736, 861, 986, 1111, 1236, 2486, 3736, 4986, 6236, 7486, 8736, 9986, 11236, 12486, 24986, 37486, 49986, 62486, 74986, 87486, 99986, 112486, 124986
Offset: 0
Programs
-
Haskell
import Data.List (elemIndex) import Data.Maybe (fromJust) a077495 n = fromJust $ elemIndex n $ map a007953 a008590_list a077495_list = map a077495 [0..] -- Reinhard Zumkeller, Dec 09 2011
Formula
From Robert Israel, Nov 19 2022: (Start) G.f.: -x^24*(985*x^9 - 125*x^8 - 125*x^7 - 125*x^6 - 125*x^5 - 125*x^4 - 125*x^3 - 125*x^2 - 125*x - 111)/((x - 1)*(10*x^9 - 1)) + 112*x^23 + 86*x^22 + 87*x^21 + 61*x^20 + 62*x^19 + 36*x^18 + 37*x^17 + 11*x^16 + 12*x^15 + 22*x^14 + 23*x^13 + 6*x^12 + 7*x^11 + 8*x^10 + 9*x^9 + x^8 + 2*x^7 + 3*x^6 + 4*x^5 + 5*x^4 + 15*x^3 + 25*x^2 + 125*x.
For n >= 24, a(n) = 125*A051885(n-24) + 111. (End)
Extensions
Corrected and extended by Ray Chandler, Aug 03 2003
Missing a(0)=0 added and offset adjusted by Reinhard Zumkeller, Dec 09 2011