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A181427 n+[n^2 if n is odd or n^3 if n is even]. 1
2, 10, 12, 68, 30, 222, 56, 520, 90, 1010, 132, 1740, 182, 2758, 240, 4112, 306, 5850, 380, 8020, 462, 10670, 552, 13848, 650, 17602, 756, 21980, 870, 27030, 992, 32800, 1122, 39338, 1260, 46692, 1406, 54910, 1560, 64040, 1722, 74130, 1892, 85228, 2070 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(2k+1) = 2*A000384(k+1) (k in A001477). [From Bruno Berselli, Oct 20 2010]

LINKS

B. Berselli, Table of n, a(n) for n = 1..10000. [From Bruno Berselli, Oct 20 2010]

Index entries for linear recurrences with constant coefficients, signature (0,4,0,-6,0,4,0,-1).

FORMULA

n+n^{2(n mod 2)+3(1-(n mod 2)}

a(n) = n+n^((5+(-1)^n)/2) = n*(1+A065679(n)).

G.f.: 2*x*(1+5*x+2x^2+14*x^3-3*x^4+5*x^5)/(1-x^2)^4.

a(n)-4*a(n-2)+6*a(n-4)-4*a(n-6)+a(n-8) = 0 for n>8.

a(2n)= A034262(2n). a(2n+1) = A002939(n+1).

EXAMPLE

For n=5, 5+5^2=30 and n=6 6+6^3=222

MATHEMATICA

If[OddQ[ # ], #+#^2, #+#^3]&/@Range[50] [From Harvey P. Dale, Nov 03 2010]

CROSSREFS

Sequence in context: A080981 A106455 A209445 * A055697 A055705 A156430

Adjacent sequences:  A181424 A181425 A181426 * A181428 A181429 A181430

KEYWORD

nonn,easy

AUTHOR

Dinesh Panchamia (dgpanchamia(AT)gmail.com), Oct 19 2010

EXTENSIONS

Formulas and more terms from R. J. Mathar and Bruno Berselli, Oct 19 2010

STATUS

approved

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Last modified March 22 10:07 EDT 2019. Contains 321421 sequences. (Running on oeis4.)