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A026806 a(n) = number of numbers k such that only one partition of n has least part k. 1
1, 2, 1, 2, 2, 2, 2, 3, 2, 3, 3, 3, 3, 4, 3, 4, 4, 4, 4, 5, 4, 5, 5, 5, 5, 6, 5, 6, 6, 6, 6, 7, 6, 7, 7, 7, 7, 8, 7, 8, 8, 8, 8, 9, 8, 9, 9, 9, 9, 10, 9, 10, 10, 10, 10, 11, 10, 11, 11, 11, 11, 12, 11, 12, 12, 12, 12, 13, 12, 13, 13, 13, 13, 14, 13, 14, 14, 14, 14, 15, 14, 15, 15, 15, 15 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

FORMULA

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

a(n) = A008615(n+6) = 1 + A008615(n), n>0.

MAPLE

seq(1+floor(n/2)-floor(n/3), n = 0..90); # G. C. Greubel, Nov 09 2019

MATHEMATICA

Rest[CoefficientList[Series[x(1+2x-x^3-x^4)/((1-x^2)(1-x^3)), {x, 0, 90}], x]]  (* Harvey P. Dale, Apr 22 2011 *)

Table[1 + Floor[n/2] - Floor[n/3], {n, 90}] (* G. C. Greubel, Nov 09 2019 *)

PROG

(PARI) a(n)=if(n<1, 0, 1+(n\2)-(n\3))

(MAGMA) [1+Floor(n/2)-Floor(n/3): n in [1..90]]; // G. C. Greubel, Nov 09 2019

(Sage) [1+floor(n/2)-floor(n/3) for n in (1..40)] # G. C. Greubel, Nov 09 2019

(GAP) List([1..90], n-> 1+Int(n/2)-Int(n/3) ); # G. C. Greubel, Nov 09 2019

CROSSREFS

Cf. A008615.

Sequence in context: A187035 A008615 A103221 * A261348 A320536 A298783

Adjacent sequences:  A026803 A026804 A026805 * A026807 A026808 A026809

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified February 28 06:55 EST 2020. Contains 332321 sequences. (Running on oeis4.)