login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 


Sum of all parts that are not the smallest part (counted with multiplicity) of all partitions of n.
2

%I #21 Feb 21 2017 02:38:19

%S 0,0,2,5,16,27,59,96,164,260,415,606,923,1336,1911,2698,3787,5203,

%T 7142,9646,12962,17295,22902,30063,39315,51104,66013,84898,108658,

%U 138397,175593,221872,279207,350248,437607,545093,676764,837873,1033961,1272730,1562137

%N Sum of all parts that are not the smallest part (counted with multiplicity) of all partitions of n.

%H Alois P. Heinz, <a href="/A213359/b213359.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A066186(n) - A092309(n).

%F G.f.: Sum_{i>0}(x^i/(1-x^i))(Sum_{j>i}(j*x^j/(1-x^j))/Product_{j>i}(1-x^j)) (obtained by logarithmic differentiation of the bivariate g.f. given in A268189). - _Emeric Deutsch_, Feb 02 2016

%e a(4) = 5 because the partitions of 4 are [1,1,1,1], [1,1,2], [1,3], [2,2], and [4], having sum of parts that are not the smallest 0, 2, 3, 0, and 0, respectively, and 0 + 2 + 3 + 0 + 0 = 5. - _Emeric Deutsch_, Feb 02 2016

%p g := add(x^i*add(j*x^j/(1-x^j), j = i+1 .. 80)/((1-x^i)*mul(1-x^j, j = i+1 .. 80)), i = 1 .. 80): gser := series(g, x = 0, 55): seq(coeff(gser, x, n), n = 1 .. 40); # _Emeric Deutsch_, Feb 02 2016

%t max = 42; gser = Sum[x^i*Sum[j*x^j/(1-x^j), {j, i+1, max}]/((1-x^i)* Product[1-x^j, {j, i+1, max}]), {i, 1, max}]+O[x]^max; CoefficientList[ gser, x] // Rest (* _Jean-François Alcover_, Feb 21 2017, after _Emeric Deutsch_ *)

%Y Cf. A066186, A092269, A092309, A268189.

%K nonn

%O 1,3

%A _Omar E. Pol_, Jan 08 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 20 17:15 EDT 2024. Contains 376075 sequences. (Running on oeis4.)