A182184 a(1)= 0; for n > 1, a(n) = a(n-1) - sopf(n) if that number is positive, otherwise a(n)= a(n-1)+ sopf(n), where sopf(n) is the sum of the distinct primes dividing n (A008472).

0, 2, 5, 3, 8, 3, 10, 8, 5, 12, 1, 6, 19, 10, 2, 0, 17, 12, 31, 24, 14, 1, 24, 19, 14, 29, 26, 17, 46, 36, 5, 3, 17, 36, 24, 19, 56, 35, 19, 12, 53, 41, 84, 71, 63, 38, 85, 80, 73, 66, 46, 31, 84, 79, 63, 54, 32, 1, 60, 50, 111, 78, 68, 66, 48, 32, 99, 80, 54, 40

Offset

1,2

Comments

a(n) = 0 for n = 16, 222, 4298, 16652, 37783, 256263, 414054, 530270, ...

Links

Michel Lagneau, Table of n, a(n) for n = 1..10000

Maple

with(numtheory):a0:=0:for n from 2 to 100 do: x:=factorset(n):n1:=nops(x): p:=sum(x[i], i=1..n1):a1:=a0-p:if a1< 0 then a1:=a0+p:else fi: printf(`%d, `, a1): a0:=a1: od:

Crossrefs

Cf. A008472, A185112.

Sequence in context: A021398 A186631 A359478 * A115318 A338060 A169856

Adjacent sequences: A182181 A182182 A182183 * A182185 A182186 A182187

Keyword

nonn

Author

Michel Lagneau, Apr 17 2012

Status

approved