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A235382 a(n) = smallest number of unit squares required to enclose n units of area. 5
4, 8, 10, 12, 12, 14, 14, 16, 16, 16, 18, 18, 18, 20, 20, 20, 20, 22, 22, 22, 22, 24, 24, 24, 24, 24, 26, 26, 26, 26, 26, 28, 28, 28, 28, 28, 28, 30, 30, 30, 30, 30, 30, 32, 32, 32, 32, 32, 32, 32, 34, 34, 34, 34, 34, 34, 34, 36, 36, 36, 36, 36 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Result attributed to the students Daring, et al., in the links section.

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 0..10000

E. Daring, I. Guadarrama, S. Sprague, C. Winterer, WhaleConjecture.

E. Daring, I. Guadarrama, S. Sprague, C. Winterer, The Whale Theorem. (PDF contains incomplete proof.)

Kival Ngaokrajang, Illustration of initial terms

FORMULA

a(n) = 2*ceiling(2*sqrt(n)) + 4.

a(n) = A027709(n) + 4.

a(n) = 2*A027434(n) + 4, n>0.

MATHEMATICA

Table[2 Ceiling[2 Sqrt[n]] + 4, {n, 0, 49}] (* Michael De Vlieger, Jul 21 2016 *)

PROG

(PARI) a(n)=if(n, 2*sqrtint(4*n-1)+6, 4) \\ Charles R Greathouse IV, Jan 09 2014

(MAGMA) [2*Ceiling(2*Sqrt(n))+4: n in [0..70]]; // Vincenzo Librandi, Jul 27 2016

CROSSREFS

Cf. A027434, A027709, A232091.

Sequence in context: A246357 A265378 A319606 * A287201 A310973 A310974

Adjacent sequences:  A235379 A235380 A235381 * A235383 A235384 A235385

KEYWORD

nonn,easy

AUTHOR

L. Edson Jeffery, Jan 08 2014

STATUS

approved

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Last modified February 27 06:03 EST 2020. Contains 332299 sequences. (Running on oeis4.)