

A095238


a(1) = 1, a(n) = n*(sum of all previous terms mod n).


1



1, 2, 0, 12, 0, 18, 35, 32, 9, 90, 11, 72, 117, 98, 30, 240, 34, 162, 247, 200, 63, 462, 69, 288, 425, 338, 108, 756, 116, 450, 651, 512, 165, 1122, 175, 648, 925, 722, 234, 1560, 246, 882, 1247, 968, 315, 2070, 329, 1152, 1617, 1250, 408, 2652, 424, 1458, 2035
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OFFSET

1,2


COMMENTS

An open question is whether the sequence contains zeros except for the 3rd and the 5th number. I checked this up to a(10000), which happens to be 99990000.  Johan Claes, Jun 16 2004


LINKS



FORMULA

Appears to satisfy a linear recurrence with characteristic polynomial (1+x)(1+x^3)^2(1x^3)^3 (checked up to n = 10^4).  Ralf Stephan, Dec 04 2004


EXAMPLE

a(6) = 6*((1 + 2 + 0 + 12 + 0) mod 6) = 18.


MAPLE



MATHEMATICA

a[1] = 1; a[n_] := a[n] = n*Mod[Sum[a[i], {i, n  1}], n]; Table[ a[n], {n, 55}] (* Robert G. Wilson v, Jun 16 2004 *)


PROG

(PARI) a=vector(1000); a[1]=1; for(i=2, 1000, a[i]=i*lift(Mod(sum(j=1, i1, a[j]), i)))


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



