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A346155
Partial sums of A007978.
1
2, 5, 7, 10, 12, 16, 18, 21, 23, 26, 28, 33, 35, 38, 40, 43, 45, 49, 51, 54, 56, 59, 61, 66, 68, 71, 73, 76, 78, 82, 84, 87, 89, 92, 94, 99, 101, 104, 106, 109, 111, 115, 117, 120, 122, 125, 127, 132, 134, 137, 139, 142, 144, 148, 150, 153, 155, 158, 160, 167
OFFSET
1,1
LINKS
FORMULA
a(n) ~ (1 + A064859) * n. - Amiram Eldar, Jul 11 2021
EXAMPLE
If b(n) is least non-divisor of n then, a(6) = b(1)+b(2)+b(3)+b(4)+b(5)+b(6) => 2+3+2+3+2+4 = 16.
MATHEMATICA
lnd[n_] := Module[{k = 2}, While[Divisible[n, k], k++]; k]; Accumulate @ Array[lnd, 100] (* Amiram Eldar, Jul 11 2021 *)
PROG
(PARI) f(n) = {my(k=2); while(!(n % k), k++); k; } \\ A007978
a(n) = sum(k=1, n, f(k)); \\ Michel Marcus, Jul 11 2021
CROSSREFS
Sequence in context: A292664 A206807 A182773 * A298869 A219666 A026340
KEYWORD
nonn
AUTHOR
Shobhit Tewari, Jul 09 2021
STATUS
approved