A144916 -id:A144916 - cp's OEIS frontend

A144917 a(n) is the maximal odd value attained by A144916(n).

1, 3, 7, 13, 19, 25, 31, 37, 43, 49, 55, 61, 67, 73, 79, 85, 91, 97, 103, 109, 115, 121, 127, 133, 139, 145, 151, 157, 163, 169, 175, 181, 187, 193, 199, 205, 211, 217, 223, 229, 235, 241, 247, 253, 259, 265, 271, 277, 283, 289, 295, 301, 307, 313, 319, 325, 331

Offset: 1

Reikku Kulon, Sep 25 2008

Most of these are primes or semiprimes.

Is a(n) = A271114(n-2) for n>=3 ? - R. J. Mathar, Jun 21 2025

Cf. A016921, A144912, A144916

A184635 a(n) = floor(1/{(n+n^4)^(1/4)}), where {} = fractional part.

Original entry on oeis.org

5, 16, 36, 64, 100, 144, 196, 256, 324, 400, 484, 576, 676, 784, 900, 1024, 1156, 1296, 1444, 1600, 1764, 1936, 2116, 2304, 2500, 2704, 2916, 3136, 3364, 3600, 3844, 4096, 4356, 4624, 4900, 5184, 5476, 5776, 6084, 6400, 6724, 7056, 7396, 7744, 8100, 8464

Offset: 1

Clark Kimberling, Jan 18 2011

nonn

Index entries for linear recurrences with constant coefficients, signature (3, -3, 1).

Cf. A184536, A144916, A016742.

p[n_]:=FractionalPart[(n^4+n)^(1/4)];
q[n_]:=Floor[1/p[n]];
Table[q[n], {n, 1, 80}]
FindLinearRecurrence[Table[q[n], {n, 1, 1000}]]
Join[{5},LinearRecurrence[{3,-3,1},{16,36,64},45]] (* Ray Chandler, Aug 02 2015 *)

a(n) = floor(1/{(n+n^4)^(1/4)}), where {} = fractional part.

It appears that a(n)=3a(n-1)-3a(n-2)+a(n-3) for n>=5, and that a(n)=4*n^2 for n>=2.

cp's OEIS Frontend

A144917 a(n) is the maximal odd value attained by A144916(n).

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A184635 a(n) = floor(1/{(n+n^4)^(1/4)}), where {} = fractional part.

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