A194545 Total sum of nonprime parts in all partitions of n.

0, 1, 2, 4, 11, 16, 33, 48, 89, 134, 214, 305, 478, 663, 976, 1356, 1934, 2617, 3654, 4877, 6652, 8808, 11772, 15386, 20329, 26308, 34249, 43987, 56651, 72079, 92008, 116171, 146967, 184381, 231399, 288398, 359581, 445426, 551721, 679868, 837238, 1026256

Offset: 0

Author

Omar E. Pol, Nov 20 2011

Keywords

• nonn

Examples

			For n = 6 we have:
--------------------------------------
.                          Sum of
Partitions             nonprime parts
--------------------------------------
6 .......................... 6
3 + 3 ...................... 0
4 + 2 ...................... 4
2 + 2 + 2 .................. 0
5 + 1 ...................... 1
3 + 2 + 1 .................. 1
4 + 1 + 1 .................. 6
2 + 2 + 1 + 1 .............. 2
3 + 1 + 1 + 1 .............. 3
2 + 1 + 1 + 1 + 1 .......... 4
1 + 1 + 1 + 1 + 1 + 1 ...... 6
--------------------------------------
Total ..................... 33
So a(6) = 33.
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A018252, A066186, A073118, A194544.

Programs

Maple

b:= proc(n, i) option remember; local h, j, t;
      if n<0 then [0, 0]
    elif n=0 then [1, 0]
    elif i<1 then [0, 0]
    else h:= [0, 0];
         for j from 0 to iquo(n, i) do
           t:= b(n-i*j, i-1);
           h:= [h[1]+t[1], h[2]+t[2]+`if`(isprime(i), 0, t[1]*i*j)]
         od; h
      fi
    end:
a:= n-> b(n, n)[2]:
seq(a(n), n=0..50);  # Alois P. Heinz, Nov 20 2011

Mathematica

b[n_, i_] := b[n, i] = Module[{h, j, t}, Which[n<0, {0, 0}, n==0, {1, 0}, i < 1, {0, 0}, True, h = {0, 0}; For[j = 0, j <= Quotient[n, i], j++, t = b[n-i*j, i-1]; h = {h[[1]] + t[[1]], h[[2]] + t[[2]] + If[PrimeQ[i], 0, t[[1]]*i*j]}]; h]]; a[n_] := b[n, n][[2]]; Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Nov 03 2015, after Alois P. Heinz *)

Formula

a(n) = A066186(n) - A073118(n).

Extensions

More terms from Alois P. Heinz, Nov 20 2011