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A048512
a(n) = T(7,n), array T given by A048505.
3
1, 65, 210, 536, 1264, 2880, 6448, 14288, 31440, 68816, 149968, 325584, 704464, 1519568, 3268560, 7012304, 15007696, 32047056, 68288464, 145227728, 308281296, 653262800, 1382023120, 2919235536, 6157238224, 12968787920, 27279753168, 57310969808, 120259084240
OFFSET
0,2
COMMENTS
n-th difference of a(n), a(n-1), ..., a(0) is (64, 81, 100, 121, ...).
FORMULA
a(n) = (n^2+29*n+196)*2^(n-2) - 48. - Ralf Stephan, Feb 05 2004
From Colin Barker, Feb 25 2015: (Start)
a(n) = 7*a(n-1) - 18*a(n-2) + 20*a(n-3) - 8*a(n-4).
G.f.: (216*x^3-227*x^2+58*x+1)/((x-1)*(2*x-1)^3). (End)
E.g.f.: exp(x)*(exp(x)*(49 + 15*x + x^2) - 48). - Elmo R. Oliveira, Oct 30 2025
PROG
(Magma) [(n^2+29*n+196) * 2^(n-2) - 48: n in [0..30]]; // Vincenzo Librandi, Sep 26 2011
(PARI) Vec((216*x^3-227*x^2+58*x+1)/((x-1)*(2*x-1)^3) + O(x^100)) \\ Colin Barker, Feb 25 2015
CROSSREFS
Cf. A048505.
Sequence in context: A200867 A175795 A056777 * A237039 A305157 A038637
KEYWORD
nonn,easy
EXTENSIONS
a(26) onward corrected by Sean A. Irvine, Nov 02 2025
STATUS
approved