

A061008


a(n) = Sum_{j=1..n} ((n1)! mod n).


4



0, 1, 2, 4, 5, 5, 6, 6, 6, 6, 7, 7, 8, 8, 8, 8, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 12, 12, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 16, 16, 16, 16, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 19, 19, 20, 20, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 23, 23, 23
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OFFSET

1,3


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..5000


FORMULA

a(n) = a(n1) + A061007(n) = A061009(n) + 2. For n > 3, a(n) = pi(n) + 2 where pi(n) = A000720(n) is the number of primes less than or equal to n.


EXAMPLE

a(6) = 5 since (1 mod 1) + (1 mod 2) + (2 mod 3) + (6 mod 4) + (24 mod 5) + (120 mod 6) = 0 + 1 + 1 + 2 + 1 + 0 = 5.


MAPLE

P:=proc(n) local a, i, k, w; a:=0; print(a); for i from 1 by 1 to n do w:=((i1)! mod (i+1)); a:=a+w; print(a); od; end: P(1000); # Paolo P. Lava, Apr 23 2007


MATHEMATICA

Join[{0, 1, 2}, a[n_]:= 2 + PrimePi[n]; Table[a[n], {n, 4, 100}]] (* Vincenzo Librandi, Aug 11 2017 *)


PROG

(MAGMA) [0, 1, 2] cat [ 2+#PrimesUpTo(n): n in [4..200] ]; // Vincenzo Librandi, Aug 11 2017


CROSSREFS

Cf. A000040, A000142, A061006, A061007, A061009.
Sequence in context: A227401 A131813 A083038 * A256720 A091988 A023824
Adjacent sequences: A061005 A061006 A061007 * A061009 A061010 A061011


KEYWORD

nonn


AUTHOR

Henry Bottomley, Apr 12 2001


STATUS

approved



