|
| |
|
|
A114708
|
|
a(n) = A114707(n) - A114707(n-1) = the number of distinct primes dividing n but not A114707(n-1).
|
|
1
| |
|
|
1, 1, 1, 1, 2, 0, 1, 1, 2, 0, 2, 0, 2, 0, 1, 1, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 3, 1, 1, 2, 1, 2, 1, 1, 2, 2, 1, 1, 3, 1, 2, 2, 2, 1, 1, 1, 0, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 0, 2, 1, 1, 1, 1, 2, 1, 2, 1, 1, 2, 2, 2, 3, 1, 2, 1, 1, 1, 2, 2, 1, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 0, 1, 3, 1, 2, 3, 1
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 2,5
|
|
|
COMMENTS
| First occurrence of k=0..8: 7, 2, 6, 30, 330, 4620, 46410, 570570, ..., . - Robert G. Wilson v, Dec 28 2005
|
|
|
EXAMPLE
| A114707(11) = 11. Since 2 and 3 are the 2 distinct primes that divide 12 and neither divides 11, a(12) is 2 (and A114707(12) is 2 + A114707(11) = 13).
|
|
|
MATHEMATICA
| a[1] = 1; a[n_] := a[n] = a[n - 1] + Length@Complement[First /@ FactorInteger@n, First /@ FactorInteger@a[n - 1]]; b = Array[a, 100]; Drop[b, 1] - Drop[b, -1] (from Robert G. Wilson v (rgwv(at)rgwv.com), Dec 28 2005)
|
|
|
PROG
| (PARI) {a=1; for(n=2, 106, print1(d=#setminus(Set(factor(n)[, 1]), Set(factor(a)[, 1])), ", "); a=a+d)} (Brockhaus)
|
|
|
CROSSREFS
| Cf. A114707.
Sequence in context: A116949 A204427 A178146 * A084927 A072670 A087624
Adjacent sequences: A114705 A114706 A114707 * A114709 A114710 A114711
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Leroy Quet, Dec 26 2005
|
|
|
EXTENSIONS
| More terms from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Robert G. Wilson v (rgwv(at)rgwv.com), Dec 27 2005
|
| |
|
|
