OFFSET
1,1
COMMENTS
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
N:= 1000: # for all terms before the first term > N
taus:= map(numtheory:-tau, [$1..N]):
for n from 1 to N do
found:= false:
for k from n+1 to N while not found do
if taus[k]>=taus[n] then found:= true; A[n]:= k fi
od;
if not found then break fi
od:
seq(A[i], i=1..n-1); # Robert Israel, Jul 23 2019
MATHEMATICA
kmax[n_] := 2 n;
a[n_] := Module[{tau = DivisorSigma[0, n], k},
For[k = n + 1, k <= kmax[n], k++,
If[DivisorSigma[0, k] >= tau, Return[k]]];
Print["a(n) = k not found for n = ", n]];
Array[a, 100] (* Jean-François Alcover, Dec 15 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Sep 01 2005
STATUS
approved