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A002466
A jumping problem.
(Formerly M1066 N0402)
1
1, 1, 2, 4, 7, 13, 17, 30, 60, 107, 197, 257, 454, 908, 1619, 2981, 3889, 6870, 13740, 24499, 45109, 58849, 103958, 207916, 370723, 682597, 890513, 1573110, 3146220, 5609843, 10329173, 13475393, 23804566, 47609132, 84889091, 156302789
OFFSET
1,3
REFERENCES
A. P. Domoryad, Mathematical Games and Pastimes. Macmillan, NY, 1964, p. 259.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
FORMULA
a(1) = a(2) = 1, a(3) = 2, a(5*k+2) = a(5*k+1) + a(5*k-1), a(5*k+3) = a(5*k+2) + a(5*k+1), a(5*k+b) = a(5*k+b-1) + a(5*k+b-2) + a(5*k+b-3) for b=-1,0,1 [From Domoryad]. - Sean A. Irvine, Apr 21 2016
From Chai Wah Wu, Dec 20 2019: (Start)
a(n) = 15*a(n-5) + 2*a(n-10) for n > 10.
G.f.: x*(-2*x^9 - 2*x^6 + 2*x^5 - 7*x^4 - 4*x^3 - 2*x^2 - x - 1)/(2*x^10 + 15*x^5 - 1). (End)
MATHEMATICA
A002466list[nmax_]:=LinearRecurrence[{0, 0, 0, 0, 15, 0, 0, 0, 0, 2}, {1, 1, 2, 4, 7, 13, 17, 30, 60, 107}, nmax]; A002466list[50] (* Paolo Xausa, Jun 26 2023 *)
CROSSREFS
Sequence in context: A002152 A163522 A255173 * A162842 A164901 A262744
KEYWORD
nonn,easy
EXTENSIONS
More terms from Sean A. Irvine, Apr 21 2016
STATUS
approved