A116137 a(0) = 1 and a(n) = a(n-1) + A116212(n), where A116212 is the list of the positive divisors of each term of this sequence.

1, 2, 3, 5, 6, 9, 10, 15, 16, 18, 21, 27, 28, 31, 40, 41, 43, 48, 58, 59, 62, 67, 82, 83, 85, 89, 97, 113, 114, 116, 119, 125, 134, 152, 153, 156, 163, 184, 185, 188, 197, 224, 225, 227, 231, 238, 252, 280, 281, 312, 313, 315, 319, 324, 332, 342, 362, 402, 403, 444

Offset

0,2

Links

John Tyler Rascoe, Table of n, a(n) for n = 0..10000

Example

a(11) = a(10) + A116212(11).
A116212 begins: 1;1,2;1,3;1,5;1,2,3,6;1,3,9;...
So a(11) = 21 + 6 = 27.

Prog

(Python)
from sympy import divisors
def A116137_list(max_n):
    A, z = [1], 0
    while len(A) <= max_n:
        A.extend((A[-1]+d) for d in divisors(A[z])); z += 1
    return(A[:max_n+1]) # John Tyler Rascoe, Nov 26 2023

Crossrefs

Cf. A116212.

Sequence in context: A025523 A173382 A128689 * A178611 A293976 A173492

Adjacent sequences: A116134 A116135 A116136 * A116138 A116139 A116140

Keyword

nonn,easy

Author

Leroy Quet, Apr 08 2007

Extensions

More terms from R. J. Mathar, Aug 31 2007

Edited by John Tyler Rascoe, Nov 26 2023

Status

approved