id:A068108 - OEIS Search Results

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a(1) = 1; a(n+1) = sum{k|n k<=sqrt(n)} a(k) where sum is over the positive divisors k of n with k <= sqrt(n).

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1, 1, 1, 1, 2, 1, 2, 1, 2, 2, 2, 1, 3, 1, 2, 2, 3, 1, 3, 1, 3, 2, 2, 1, 4, 3, 2, 2, 3, 1, 5, 1, 3, 2, 2, 3, 5, 1, 2, 2, 5, 1, 4, 1, 3, 4, 2, 1, 5, 3, 4, 2, 3, 1, 4, 3, 5, 2, 2, 1, 7, 1, 2, 4, 4, 3, 4, 1, 3, 2, 6, 1, 6, 1, 2, 4, 3, 3, 4, 1, 6, 4, 2, 1, 7, 3, 2, 2, 4, 1, 8, 3, 3, 2, 2, 3, 6, 1, 4, 4, 7, 1, 4, 1, 4 (list; graph; listen)

	OFFSET	`1,5`
	LINKS	`Leroy Quet, Home Page (listed in lieu of email address)`
	MATHEMATICA	`a[1]=1; a[n_] := a[n] = Module[{d=Divisors[n-1], s=0, i=1}, While[i<=Length[d] && d[[i]]<=Sqrt[n-1], s=s+a[d[[i]]]; i++ ]; s]; Table[a[n], {n, 150}] (T. D. Noe)`
	CROSSREFS	`Sequence in context: A106490 A122375 A038548 this_sequence A113309 A062362 A084113` `Adjacent sequences: A068105 A068106 A068107 this_sequence A068109 A068110 A068111`
	KEYWORD	`nonn`
	AUTHOR	`Leroy Quet, Mar 22 2002`
	EXTENSIONS	`More terms from T. D. Noe (noe(AT)sspectra.com), Nov 03 2004`

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Last modified November 25 08:46 EST 2009. Contains 167481 sequences.

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