A111241 a(n) = A109735(n)/A109890(n+1).

1, 1, 3, 2, 2, 4, 9, 5, 4, 3, 5, 5, 9, 5, 4, 8, 15, 8, 12, 27, 52, 7, 4, 2, 5, 3, 6, 106, 14, 5, 9, 5, 4, 6, 107, 180, 21, 362, 121, 183, 176, 69, 59, 150, 28, 151, 232, 19, 10, 2, 11, 9, 233, 360, 247, 304, 155, 244, 195, 98, 231, 174, 196, 50, 591, 296, 198, 51, 199

Offset: 2

Author

N. J. A. Sloane, Oct 30 2005

Keywords

• nonn

Comments

This is always an integer for n>=2.

a(n) = 1 for n in A111315. When this happens A109890(n+1) makes a large jump. The corresponding values of A109890(n+1) are in A111316 (cf. A111242).

Examples

			A109735(4)=12, A109890(5)=4, so a(4) = 12/4 = 3.
		

Links

• Michael De Vlieger, Table of n, a(n) for n = 2..10000

Crossrefs

Cf. A109735, A109890, A094340, A111315, A111316, A111242.

Different from A094339.

Programs

Mathematica

nn = 71; c[_] := False;
Array[Set[{a[#], c[#]}, {#, True}] &, 2]; s = a[1] + a[2];
Reap[Do[k = SelectFirst[Divisors[s], ! c[#] &];
    c[k] = True; Sow[s/k];
s += k, {n, 3, nn}] ][[-1, 1]] (* Michael De Vlieger, Apr 26 2024 *)

Formula

a(n) = A094340(n) for all n > 1. - David Wasserman, Jan 06 2009