A032635 -id:A032635 - cp's OEIS frontend

A152738 a(n) = floor((n^2)/phi).

0, 0, 2, 5, 9, 15, 22, 30, 39, 50, 61, 74, 88, 104, 121, 139, 158, 178, 200, 223, 247, 272, 299, 326, 355, 386, 417, 450, 484, 519, 556, 593, 632, 673, 714, 757, 800, 846, 892, 940, 988, 1038, 1090, 1142, 1196, 1251, 1307, 1365, 1423, 1483, 1545, 1607, 1671

Offset: 0

Vladimir Joseph Stephan Orlovsky, Dec 12 2008

nonn

G. C. Greubel, Table of n, a(n) for n = 0..5000

Cf. A014217, A152737, A032616, A032635.

phi:=(1+Sqrt(5))/2; [Floor(n^2/phi): n in [0..30]]; // G. C. Greubel, Sep 01 2018

Mathematica
```
a[n_]:=Floor[(n^2)/GoldenRatio];
```

a(n)=n^2\((1+sqrt(5))/2) \\ Charles R Greathouse IV, Jul 29 2011

Offset corrected by B. D. Swan, Jan 03 2009

A248469 a(n) = floor((2*n^2)/e).

Original entry on oeis.org

0, 2, 6, 11, 18, 26, 36, 47, 59, 73, 89, 105, 124, 144, 165, 188, 212, 238, 265, 294, 324, 356, 389, 423, 459, 497, 536, 576, 618, 662, 707, 753, 801, 850, 901, 953, 1007, 1062, 1119, 1177, 1236, 1297, 1360, 1424, 1489, 1556, 1625, 1695, 1766, 1839

Offset: 1

Juliann Barbella, Oct 06 2014

Cf. A032635 (floor(n^2/e)).

int a(int n) {return (int) ((2*Math.pow(x, 2))/Math.exp(1.0)); }

Table[Floor[(2 n^2)/ E ], {n, 1, 60}] (* Vincenzo Librandi, Oct 23 2014 *)

a(n) = (2*n^2)\exp(1) \\ Michel Marcus, Oct 25 2014

a(n) = floor((2*n^2)/e).

More terms from Vincenzo Librandi, Oct 23 2014

cp's OEIS Frontend

A152738 a(n) = floor((n^2)/phi).

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