Search: id:A104623 Results 1-1 of 1 results found. %I A104623 %S A104623 4,8,9,11,12,14,15,16,22,23,32,34,37,41,42,50,52,57,58,66,69,76,77,81, %T A104623 90 %N A104623 Indices of semiprime (A001358) values of Heptanacci-Lucas numbers A104621. %C A104623 The 7th-order linear recurrence A104622 (heptanacci-Lucas numbers) is a generalization of the Lucas sequence A000032. T. D. Noe and I have noted that the heptanacci-Lucas numbers have many more primes than the corresponding heptanacci (see A104414) which he found has only the first 3 primes that I identified through the first 5000 values, whereas these heptanacci-Lucas numbers have 17 primes among the first 100 values. For primes in Heptanacci-Lucas numbers, see A104622. %D A104623 Mario Catalani, "Polymatrix and Generalized Polynacci Numbers", arXiv:math.CO/ 0210201 v1, 2002 %H A104623 Eric Weisstein's World of Mathematics, Semiprime. %e A104623 A104621(4) = 15 = 3 * 5, %e A104623 A104621(8) = 247 = 13 * 19, %e A104623 A104621(9) = 493 = 17 * 29, %e A104623 A104621(11) = 1959 = 3 * 653, %e A104623 A104621(12) = 3903 = 3 * 1301, %e A104623 A104621(14) = 15487 = 17 * 911, %Y A104623 Cf. A001358. %Y A104623 Sequence in context: A073042 A094349 A118715 this_sequence A158758 A078137 A010453 %Y A104623 Adjacent sequences: A104620 A104621 A104622 this_sequence A104624 A104625 A104626 %K A104623 nonn %O A104623 0,1 %A A104623 Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 17 2005 Search completed in 0.001 seconds