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A073853
Indices of zeros in A079777.
3
0, 5, 9, 12, 24, 45, 60, 65, 179, 764, 1268, 5891, 16135, 29909, 71774, 173310, 200040, 1454560, 2485272, 86430343, 92439810, 115854652, 7208007982, 17016737751, 17589706947, 24531053552, 33113576855, 80692537585, 234365843350, 266484243960, 285357252641, 426388494035, 975986718040, 1505420538689, 43633539697333
OFFSET
1,2
COMMENTS
Let b(1) = b(2) = 1, b(k) = (b(k-1) + b(k-2)) mod k; sequence gives n such that b(n) = 0.
A079777(2^31-1) = 1103802855, and A079777(2^31) = 2117709557.
No further terms below k = 5*10^10, at which point, A079777(k-1) = 6059364906669 and A079777(k) = 29451014544130. - Luca Armstrong, Apr 07 2023
LINKS
EXAMPLE
b(3) = 2 mod 3 = 2; b(4) = (2+1) mod 4 = 3; b(5) = (3+2) mod 5 = 0, hence a(1) = 5.
MATHEMATICA
a = 0; b = 1; lst = {0}; Do[c = Mod[a + b, n]; If[c == 0, AppendTo[lst, n]; Print@n]; a = b; b = c, {n, 2, 2^31}] (* Robert G. Wilson v *)
PROG
(Java) class A073853 { public static void main(String [] args) { BigInteger an = BigInteger.ZERO ; BigInteger an1 = BigInteger.ONE ; BigInteger n = new BigInteger("2") ; for( ; ; n = n.add(BigInteger.ONE) ) { BigInteger an2 = an.add(an1).mod(n) ; if ( an2.compareTo(BigInteger.ZERO) == 0 ) System.out.println(n) ; an = an1 ; an1 = an2 ; } } } // R. J. Mathar, Dec 06 2009
CROSSREFS
A079777(n) = 0.
Sequence in context: A314649 A314650 A220187 * A070370 A277617 A103703
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Sep 02 2002
EXTENSIONS
Corrected and extended by John W. Layman, Jun 11 2003
a(23)-a(26) from Zak Seidov; a(27)-a(28) from John W. Layman; a(29)-a(34) from Charles R Greathouse IV, Dec 09 2009. (These new terms were added by N. J. A. Sloane, Dec 20 2009.)
a(35) from Luca Armstrong, Apr 07 2023
STATUS
approved