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A101758 Semiprime tribonacci numbers. 1
4, 274, 10609, 23837527729, 80641778674, 3122171529233, 408933139743937, 98513851446415969, 7015254043203144209, 1690006574433492223897, 120346786571258131649185, 2533271375725618104752561 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..12.

Eric Weisstein's World of Mathematics, Semiprime

Eric Weisstein's World of Mathematics, Tribonacci Number

Index entries for linear recurrences with constant coefficients, signature (1, 1, 1).

MATHEMATICA

Select[LinearRecurrence[{1, 1, 1}, {0, 1, 1}, 150], PrimeOmega[#]==2&] (* Harvey P. Dale, Oct 16 2012 *)

CROSSREFS

a(n) = A000073(A101757(n)).

Cf. A000073, A001358, A101757.

Sequence in context: A108134 A221081 A000320 * A134786 A290225 A190635

Adjacent sequences:  A101755 A101756 A101757 * A101759 A101760 A101761

KEYWORD

nonn

AUTHOR

Jonathan Vos Post and Ray Chandler, Dec 26 2004

STATUS

approved

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Last modified May 21 23:44 EDT 2019. Contains 323472 sequences. (Running on oeis4.)