

A178095


a(1)=a(2)=a(3)=1; thereafter a(n) = lpf(a(n1)+a(n2)+a(n3)), where lpf = "least prime factor".


3



1, 1, 1, 3, 5, 3, 11, 19, 3, 3, 5, 11, 19, 5, 5, 29, 3, 37, 3, 43, 83, 3, 3, 89, 5, 97, 191, 293, 7, 491, 7, 5, 503, 5, 3, 7, 3, 13, 23, 3, 3, 29, 5, 37, 71, 113, 13, 197, 17, 227, 3, 13, 3, 19, 5, 3, 3, 11, 17, 31, 59, 107, 197, 3, 307, 3, 313, 7, 17, 337, 19, 373, 3, 5, 3, 11, 19, 3, 3, 5, 11, 19, 5, 5, 29, 3, 37, 3, 43, 83, 3, 3, 89, 5, 97, 191, 293, 7, 491, 7
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OFFSET

1,4


COMMENTS

Has period 69, starting with the fourth term: 3, 5, 3, 11, 19, 3, 3, 5, 11, ...


LINKS

Table of n, a(n) for n=1..100.


MATHEMATICA

nxt[{a_, b_, c_}]:={b, c, FactorInteger[a+b+c][[1, 1]]}; Transpose[ NestList[ nxt, {1, 1, 1}, 100]][[1]] (* Harvey P. Dale, Aug 19 2014 *)


CROSSREFS

Cf. A178094, A020639, A175723, A177904.
Sequence in context: A205708 A089730 A105445 * A177904 A049072 A059887
Adjacent sequences: A178092 A178093 A178094 * A178096 A178097 A178098


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Dec 16 2010


STATUS

approved



