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A258016
Unlucky numbers removed at the stage three of Lucky sieve.
3
19, 39, 61, 81, 103, 123, 145, 165, 187, 207, 229, 249, 271, 291, 313, 333, 355, 375, 397, 417, 439, 459, 481, 501, 523, 543, 565, 585, 607, 627, 649, 669, 691, 711, 733, 753, 775, 795, 817, 837, 859, 879, 901, 921, 943, 963, 985, 1005, 1027, 1047, 1069, 1089, 1111, 1131, 1153, 1173, 1195, 1215, 1237, 1257, 1279, 1299, 1321, 1341, 1363, 1383, 1405
OFFSET
1,1
COMMENTS
Numbers congruent to 19 or 39 modulo 42. - Jianing Song, Apr 27 2022
FORMULA
a(n) = A047241(7*n).
a(n) = A260436(A255413(1+n)).
From Jianing Song, Apr 27 2022: (Start)
a(n) = a(n-2) + 42.
a(n) = a(n-1) + a(n-2) - a(n-3).
G.f.: (19*x+20*x^2+3*x^3)/(1-x-x^2+x^3).
E.g.f.: 3 + (21*x-3)*cosh(x) + (21*x-2)*sinh(x). (End)
PROG
(Scheme, two alternatives)
(define (A258016 n) (A047241 (* n 7)))
(define (A258016 n) (A255543bi 3 n)) ;; Code for A255543bi given in A255543.
CROSSREFS
Row 3 of A255543. Every seventh term of A047241.
Cf. also A258011.
Sequence in context: A042629 A041708 A079044 * A217731 A195048 A299964
KEYWORD
nonn,easy
AUTHOR
Antti Karttunen, Jul 27 2015
STATUS
approved