

A243283


One more than the partial sums of the characteristic function of A070003.


5



1, 1, 1, 2, 2, 2, 2, 3, 4, 4, 4, 4, 4, 4, 4, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 16
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OFFSET

1,4


COMMENTS

a(n) tells how many natural numbers <= n there are which are divisible by the square of their largest noncomposite divisor. (This definition includes 1 as it is divisible by 1^2).
a(n) = n  A243285(n).
a(1)=1 and for all n>1, a(A070003(n1)) = n, thus this sequence works as an inverse function for the injection {a(1)=1, a(n>1)=A070003(n1)} (a sequence which is an union of {1} and A070003).


LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000


PROG

(Scheme, with memoizing macro definec from Antti Karttunen's IntSeqlibrary)
(definec (A243283 n) (if (<= n 1) n (+ (A243283 ( n 1)) (if (zero? (A241917 n)) 1 0))))


CROSSREFS

One more than A243282.
Differs from A243284 for the first time at n=48. Here a(48)=10.
Cf. A070003, A102354, A243285, A057627.
Sequence in context: A069623 A076411 A217038 * A243284 A072613 A029551
Adjacent sequences: A243280 A243281 A243282 * A243284 A243285 A243286


KEYWORD

nonn


AUTHOR

Antti Karttunen, Jun 02 2014


STATUS

approved



