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A088822 a(n) is the sum of largest prime factors of numbers from 1 to n. 6
0, 2, 5, 7, 12, 15, 22, 24, 27, 32, 43, 46, 59, 66, 71, 73, 90, 93, 112, 117, 124, 135, 158, 161, 166, 179, 182, 189, 218, 223, 254, 256, 267, 284, 291, 294, 331, 350, 363, 368, 409, 416, 459, 470, 475, 498, 545, 548, 555, 560, 577, 590, 643, 646, 657, 664, 683 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = Pi^2/12 * n^2/log n + O(n^2/log^2 n). - Charles R Greathouse IV, Feb 19 2014

a(n) ~ zeta(2) * A088821(n), where zeta(2) = Pi^2/6. - Thomas Ordowski, Nov 29 2018

MATHEMATICA

-1 + Accumulate@ Array[FactorInteger[#][[-1, 1]] &, 57] (* Michael De Vlieger, Jul 23 2017 *)

PROG

(PARI) gpf(n)=if(n<4, n, n=factor(n)[, 1]; n[#n])

a(n)=sum(k=2, n, gpf(k)) \\ Charles R Greathouse IV, Feb 19 2014

(GAP) P:=List(List([2..60], n->Reversed(Factors(n))), i->i[1]);;

a:=Concatenation([0], List([1..Length(P)], i->Sum([1..i], k->P[k]))); # Muniru A Asiru, Nov 29 2018

CROSSREFS

Cf. A046670, A006530, A088821, A088823, A088824, A088825.

Sequence in context: A294146 A022758 A129232 * A080182 A001318 A024702

Adjacent sequences:  A088819 A088820 A088821 * A088823 A088824 A088825

KEYWORD

nonn

AUTHOR

Labos Elemer, Oct 22 2003

STATUS

approved

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Last modified April 21 01:53 EDT 2021. Contains 343143 sequences. (Running on oeis4.)