A140600 Grand totals of prime factors in composite runs between two primes.

2, 5, 5, 19, 5, 37, 83, 79, 59, 5, 53, 167, 5, 67, 179, 5, 239, 277, 263, 701, 479, 43, 439, 349, 17, 5, 281, 23, 29, 367, 397, 947, 1129, 29, 887, 739, 17, 149, 769, 5, 1361, 53, 43, 857, 1723, 29, 1861, 37, 2111, 53, 857, 983, 1699, 23, 907, 599, 1283, 29, 281, 23, 499

Offset

1,1

Comments

In this sequence a run consists of three or more terms, the first prime, one or more composites and the last prime. The values of the two primes are not included in the grand total of prime factors (only the prime factors in the composites).

Links

Table of n, a(n) for n=1..61.

Formula

Compute composite runs between two primes. If the grand total of prime factors in each run is also prime, add the prime grand total to the sequence.

Example

In a(6) the grand total is 37 because that is the prime sum of all the prime factors of composites in the composite run beginning at 24 (between primes 23 and 29).

Crossrefs

Cf. A140599.

Sequence in context: A165659 A154816 A367299 * A056396 A085043 A338586

Adjacent sequences: A140597 A140598 A140599 * A140601 A140602 A140603

Keyword

easy,nonn

Author

Enoch Haga, May 18 2008

Status

approved