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A072548 a(n) = sigma(n) mod PrimePi(n). 3
0, 0, 1, 0, 0, 0, 3, 1, 2, 2, 3, 2, 0, 0, 1, 4, 4, 4, 2, 0, 4, 6, 6, 4, 6, 4, 2, 0, 2, 10, 8, 4, 10, 4, 3, 2, 0, 8, 6, 3, 5, 2, 0, 8, 2, 3, 4, 12, 3, 12, 8, 6, 8, 8, 8, 0, 10, 9, 15, 8, 6, 14, 1, 12, 0, 11, 12, 1, 11, 12, 15, 11, 9, 19, 14, 12, 0, 14, 10, 11, 16, 15, 17, 16, 17, 5, 19, 18, 18 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,7

LINKS

Michael De Vlieger, Table of n, a(n) for n = 2..10000

FORMULA

a(n) = A000203(n) mod A000720(n).

MAPLE

with(numtheory): seq(modp(sigma(n), pi(n)), n=2..100); # Muniru A Asiru, Dec 10 2018

MATHEMATICA

Table[Mod[DivisorSigma[1, w], PrimePi[w]], {w, 1, 128}]

PROG

(PARI) a(n) = sigma(n) % primepi(n); \\ Michel Marcus, Dec 10 2018

(MAGMA) [SumOfDivisors(n) mod (#PrimesUpTo(n)): n in [2..100]]; // Vincenzo Librandi, Dec 10 2018

CROSSREFS

Cf. A000203, A000720, A073321, A073322, A073323, A073324.

Sequence in context: A328848 A108121 A161916 * A079399 A092155 A288725

Adjacent sequences:  A072545 A072546 A072547 * A072549 A072550 A072551

KEYWORD

nonn

AUTHOR

Labos Elemer, Aug 05 2002

STATUS

approved

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Last modified April 10 23:04 EDT 2021. Contains 342876 sequences. (Running on oeis4.)