A090343 Difference between the sums of the prime factors, including multiplicity, of n and those of n + 4.

-5, -3, -4, -2, -1, -2, -4, -1, -7, -2, 3, -1, -4, 1, -11, -1, 7, -5, -4, 0, 0, -2, 14, -2, -19, 5, -22, 1, 15, -9, 19, 0, -23, -2, -4, -1, -4, 9, -27, -4, 30, -13, -4, 4, -3, 13, 27, -6, -39, 1, 4, 4, 31, -20, -43, 1, -39, -2, 46, 0, 43, 17, -54, -9, -8, 2, -4, 9, -47, -25, 58, -11, 55, 21, -66, 10, 6, -25, -4, -1, -10, -2, 51, -3, -67

Offset: 1

Author

Charles K. Layman (cklayman(AT)juno.com), Nov 25 2003

Keywords

• sign

Examples

			a(24)=-2 because 24=2*2*2*3, 28=2*2*7 and (2+2+2+3)-(2+2+7)=-2.
		

Crossrefs

Cf. A001414, A090340, A090341, A090342.

Programs

Mathematica

Join[{-5},#[[1]]-#[[5]]&/@Partition[Table[Total[Times@@@FactorInteger[n]],{n,2,90}],5,1]] (* Harvey P. Dale, Jul 02 2022 *)

Formula

a(n) = A001414(n) - A001414(n+4). - Wesley Ivan Hurt, Aug 29 2016