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A159746
If an array is made of columns of -nacci sequences, fibo-, tribo- etc. all starting w. 1,1,2 etc, the NW to SE diagonals can be extended by computation. The above is diagonal 9. See A159741 for details.
2
55, 274, 773, 1793, 3840, 7936, 16128, 32512, 65280, 130816, 261888, 524032, 1048320, 2096896, 4194048, 8388352, 16776960, 33554176, 67108608, 134217472, 268435200, 536870656, 1073741568, 2147483392, 4294967040, 8589934336, 17179868928, 34359738112
OFFSET
1,1
FORMULA
Interpolate a(n)=(4*n^3-30*n^2+92*n+657)/3 offset 0 & b(n)=(-4*n^3+24*n^2-65*n+840)/3 offset 0. Add 55 as a leader. Binomially transform. [From Al Hakanson (hawkuu(AT)gmail.com), Jun 08 2009]
a(n) = 2^(7+n)-256 for n>=5. - R. J. Mathar, Feb 04 2021
MATHEMATICA
LinearRecurrence[{3, -2}, {55, 274, 773, 1793, 3840, 7936}, 30] (* Harvey P. Dale, Aug 18 2022 *)
CROSSREFS
Sequence in context: A296036 A286854 A020182 * A212408 A350286 A250092
KEYWORD
nonn,easy
AUTHOR
Al Hakanson (hawkuu(AT)gmail.com), Apr 20 2009
EXTENSIONS
a(7) and beyond by R. J. Mathar, Feb 04 2021
STATUS
approved