OFFSET
1,1
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
MAPLE
with(numtheory): f := [seq( `if`((sigma(i+1) > sigma(i)), i, print( )), i=1..5000)];
seq( `if`(f[i+1] - f[i] = 3, i, print( )), i=1..1000);
MATHEMATICA
Position[Differences@ Select[Range[10^4], Less @@ DivisorSigma[1, # + {0, 1}] &], 3][[All, 1]] (* Michael De Vlieger, Nov 19 2019 *)
PROG
(Haskell)
import Data.List (elemIndices)
a053235 n = a053235_list !! (n-1)
a053235_list = map (+ 1) $ elemIndices 3 a053230_list
-- Reinhard Zumkeller, May 07 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Asher Auel, Jan 10 2000
STATUS
approved