A128188 Row sums of A128187.

1, 2, 3, 5, 5, 9, 7, 13, 10, 17, 12, 23, 14, 27, 18, 32, 20, 38, 22, 44, 26, 48, 28, 56, 31, 60, 35, 66, 37, 74, 39, 80, 43, 84, 47, 93, 49, 97, 53, 105, 55, 113, 57, 119, 63, 123, 65, 133, 68, 139, 72, 145, 74, 153, 78, 161, 82, 165, 84, 177, 86, 181, 92, 188, 96, 196, 98, 202, 102, 210

Offset

1,2

Links

Table of n, a(n) for n=1..70.

Formula

a(n) = Sum_{k=1..n} A128187(n,k).

a(n) = Sum_{i=1..floor((n+2)/2)} d(n+2-2i), where d(n) is the number of divisors of n. - Wesley Ivan Hurt, Jul 12 2015

Example

a(6) = 9 = sum of row 6 terms of A128187: (3 + 3 + 1 + 1 + 1).

Maple

A128188 := proc(n)
    add(A128187(n, k), k=1..n) ;
end proc; # R. J. Mathar, Apr 16 2013
with(numtheory): A128188:=n->add(tau(n+2-2*i), i=1..floor((n+2)/2)): seq(A128188(n), n=1..100); # Wesley Ivan Hurt, Jul 12 2015

Crossrefs

Cf. A000005, A128187.

Sequence in context: A348203 A158901 A096736 * A318636 A366975 A267582

Adjacent sequences: A128185 A128186 A128187 * A128189 A128190 A128191

Keyword

nonn

Author

Gary W. Adamson, Feb 17 2007

Status

approved