|
Search: id:A141808
|
|
|
| A141808 |
|
If p^b(n,p) is the largest power of the prime p to divide n, then the positive integer non-prime-power n is included in the sequence if p(1)^b(n,p(1)) = p(2)^b(n,p(2))+1 = p(3)^b(n,p(3))+2 =...= p(k)^b(n,p(k))+k-1, where (p(1),p(2),p(3),...,p(k)) is some permutation of the distinct primes that divide n. |
|
+0
2
|
| |
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Sequence A141807 consists of the prime-powers and the terms of A141808 together.
|
|
EXAMPLE
|
The prime-factorization of 60 is 2^2 *3^1 *5^1. Since 60 is not a prime power and since 5^1 = 2^2 +1 = 3^1 +2 (ie, the prime powers, in some order, occur in an arithmetic progression with a difference of 1 between consecutive terms), then 60 is included in the sequence.
|
|
CROSSREFS
|
Cf. A141807.
Sequence in context: A130199 A117343 A028611 this_sequence A144187 A055458 A078472
Adjacent sequences: A141805 A141806 A141807 this_sequence A141809 A141810 A141811
|
|
KEYWORD
|
more,nonn
|
|
AUTHOR
|
Leroy Quet (q1qq2qqq3qqqq(AT)yahoo.com), Jul 07 2008
|
|
|
Search completed in 0.002 seconds
|
