id:A068312 - OEIS Search Results

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Arithmetic derivative of triangular numbers.

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2

0, 1, 5, 7, 8, 10, 32, 60, 39, 16, 61, 71, 20, 71, 244, 212, 111, 123, 143, 247, 131, 34, 380, 520, 155, 378, 621, 275, 247, 263, 1008, 1280, 271, 239, 951, 795, 56, 343, 1256, 1004, 431, 451, 581, 1443, 942, 70, 2092, 2492, 840 (list; graph; listen)

	OFFSET	`1,3`
	FORMULA	`a(n) = A003415(A000217(n)).`
	EXAMPLE	`a(7) = d(78/2) = d(28) = d(214) = d(2)14 + 2d(14) =` `= 114 + 2d(27) = 14 + 2(2d(7) + d(2)7) =` `= 14 + 2(21 + 17) = 14 + 29 = 14 + 18 = 32;` `where d(n) = A003415(n)` `with d(1)=0, d(prime)=1 and d(mn)=d(m)n+m*d(n).`
	CROSSREFS	`Sequence in context: A080707 A059612 A056657 this_sequence A082097 A088299 A013635` `Adjacent sequences: A068309 A068310 A068311 this_sequence A068313 A068314 A068315`
	KEYWORD	`nonn`
	AUTHOR	`Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 25 2002`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

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