A131347 a(1)=1. a(n) = a(n-1) + (sum of the terms, from among terms a(1) through a(n-1), which are coprime to sum{k=1 to n-1} a(k)).

1, 2, 5, 11, 30, 79, 175, 448, 1199, 2489, 6928, 18265, 40489, 110610, 291341, 645395, 1633957, 2615141, 7207226, 19135622, 50845035, 106938617, 244812167, 652656533, 1686364826, 3755787245, 4816287969, 12353991673, 29473426455

Offset

1,2

Links

Table of n, a(n) for n=1..29.

Example

The sum of the first 6 terms of the sequence is 128. There are 4 terms from among the first 6 terms of the sequence that are coprime to 128 (a(1)=1, a(3)=5, a(4)=11, a(6)=79). So a(7)= a(6) + 1 + 5 + 11 + 79 = 175.

Crossrefs

Cf. A131346.

Sequence in context: A345882 A121134 A144959 * A292210 A079225 A139466

Adjacent sequences: A131344 A131345 A131346 * A131348 A131349 A131350

Keyword

nonn

Author

Leroy Quet, Jul 01 2007

Extensions

More terms from Joshua Zucker, Jul 18 2007

Status

approved