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A253909 1 together with the positive squares. 3
1, 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225, 256, 289, 324, 361, 400, 441, 484, 529, 576, 625, 676, 729, 784, 841, 900, 961, 1024, 1089, 1156, 1225, 1296, 1369, 1444, 1521, 1600, 1681, 1764, 1849, 1936, 2025, 2116, 2209, 2304, 2401, 2500 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Also, right border of A246595 arranged as an irregular triangle.

a(n) are the Engel expansion of A070910. - Benedict W. J. Irwin, Dec 15 2016

LINKS

Table of n, a(n) for n=0..50.

FORMULA

a(n) = A028310(n)^2.

a(n) = 3*a(n-1)-3*a(n-2)+a(n-3) for n>=4. - David Neil McGrath, May 23 2015

G.f.: (x^3-4*x^2+2*x-1)/(x-1)^3. - David Neil McGrath, May 25 2015

MATHEMATICA

Join[{1}, Range[50]^2] (* Alonso del Arte, Feb 23 2015 *)

Range[0, 50]^2 /. 0 -> 1 (* Robert G. Wilson v, Dec 15 2016 *)

PROG

(PARI) a(n)=max(n, 1)^2 \\ Charles R Greathouse IV, Dec 16 2016

CROSSREFS

Cf. A000290, A174902, A246595.

Sequence in context: A174902 A000290 A162395 * A221222 A144913 A018885

Adjacent sequences:  A253906 A253907 A253908 * A253910 A253911 A253912

KEYWORD

nonn,easy

AUTHOR

Omar E. Pol, Feb 12 2015

STATUS

approved

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Last modified January 17 16:43 EST 2018. Contains 297822 sequences.