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A178508 a(n) = 1, 7, A011557*(period 6: repeat 10, 13, 31, 49, 70, 97). 1
1, 7, 10, 13, 31, 49, 70, 97, 100, 130, 310, 490, 700, 970, 1000, 1300, 3100, 4900, 7000, 9700, 10000, 13000, 31000, 49000, 70000, 97000, 100000, 130000, 310000, 490000, 700000, 970000, 1000000, 1300000, 3100000, 4900000, 7000000, 9700000, 10000000 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
G.f.: x*(10*x^2+13*x^3+31*x^4+49*x^5+60*x^6+27*x^7+1+7*x)/(1-10*x^6).
a(n) = 10^floor((n-3)/6)*(45+8*cos((n-2)*Pi)+25*cos((n-2)*Pi/3)+19*cos(2*(n-2)*Pi/3)-4*sqrt(3)*(4*sin((n-2)*Pi/3)+sin(2*(n-2)*Pi/3))) for n>2. - Wesley Ivan Hurt, Jun 18 2016
MAPLE
A178508:=n->10^floor((n-3)/6)*(45+8*cos((n-2)*Pi)+25*cos((n-2)*Pi/3)+19*cos(2*(n-2)*Pi/3)-4*sqrt(3)*(4*sin((n-2)*Pi/3)+sin(2*(n-2)*Pi/3))): 1, 7, seq(A178508(n), n=3..50); # Wesley Ivan Hurt, Jun 18 2016
MATHEMATICA
Join[{1, 7}, Flatten[Table[10^n {10, 13, 31, 49, 70, 97}, {n, 0, 6}]]] (* or *) Join[{1, 7}, LinearRecurrence[{0, 0, 0, 0, 0, 10}, {10, 13, 31, 49, 70, 97}, 50]] (* Harvey P. Dale, Nov 19 2013 *)
PROG
(PARI) a=[1, 7, 10, 13, 31, 49, 70, 97]; for(i=1, 99, a=concat(a, 10*a[#a-5])); a \\ Charles R Greathouse IV, Jun 01 2011
CROSSREFS
Sequence in context: A114961 A219045 A199427 * A123834 A064629 A215579
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, May 29 2010
EXTENSIONS
Dissassociated with sums-of-squares sequences by R. J. Mathar, Jun 07 2010
STATUS
approved

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Last modified March 28 16:58 EDT 2024. Contains 371254 sequences. (Running on oeis4.)