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A174938 a(n) = Sum_{k<=n} A007955(k) * A007955(n-k+1), where A007955(m) = product of divisors of m. 0
1, 4, 10, 28, 51, 140, 252, 452, 953, 1164, 2974, 5676, 13531, 14828, 40744, 27260, 146845, 55372, 288174, 177700, 574867, 204916, 3721652, 988332, 3550621, 3267452, 11129590, 4173196, 46286551, 7402156 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..30.

EXAMPLE

For n = 4, A007955(n) = b(n): a(4) = b(1)*b(4) + b(2)*b(3) + b(3)* b(2) + b(4)*b(1) = 1*8 + 2*3 + 3*2 + 8*1 = 28.

CROSSREFS

Sequence in context: A186278 A222963 A257028 * A032248 A092504 A038579

Adjacent sequences:  A174935 A174936 A174937 * A174939 A174940 A174941

KEYWORD

nonn

AUTHOR

Jaroslav Krizek, Apr 02 2010

STATUS

approved

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Last modified March 26 16:33 EDT 2019. Contains 321510 sequences. (Running on oeis4.)