A332559 a(n) = n + A332558(n) + 1.

6, 6, 6, 8, 10, 12, 12, 12, 15, 15, 18, 18, 20, 20, 20, 24, 24, 24, 24, 24, 28, 30, 30, 30, 30, 35, 35, 35, 36, 36, 40, 40, 40, 40, 40, 45, 45, 45, 45, 48, 48, 48, 54, 54, 54, 56, 56, 56, 56, 60, 60, 60, 60, 60, 60, 63, 70, 70, 70, 70, 70, 70, 70, 72, 72, 72

Offset: 1

Author

Scott R. Shannon and N. J. A. Sloane, Feb 24 2020

Keywords

• nonn

Links

• Robert Israel, Table of n, a(n) for n = 1..10000
• J. S. Myers, R. Schroeppel, S. R. Shannon, N. J. A. Sloane, and P. Zimmermann, Three Cousins of Recaman's Sequence, arXiv:2004:14000 [math.NT], April 2020.

Crossrefs

Cf. A061836, A332558, A332560, A332561.

Programs

Maple

f:= proc(n) local k,p;
  p:= n;
  for k from 1 do
    p:= p*(n+k);
    if (p/(n+k+1))::integer then return n+k+1 fi
  od
end proc:
map(f, [$1..100]); # Robert Israel, Feb 25 2020

Mathematica

a[n_] := Module[{k, p = n}, For[k = 1, True, k++, p *= (n+k); If[Divisible[p, n+k+1], Return[n+k+1]]]];
Array[a, 100] (* Jean-François Alcover, Jul 18 2020, after Maple *)

Python

def a(n):
    k, p = 1, n*(n+1)
    while p%(n+k+1): k += 1; p *= (n+k)
    return n + k + 1
print([a(n) for n in range(1, 67)]) # Michael S. Branicky, Jun 06 2021