A084410 - OEIS

This site is supported by donations to The OEIS Foundation.

A084410

First column of triangle A084408.

1, 2, 5, 4, 13, 10, 31, 20, 30, 42, 61, 55, 109, 70, 88, 108, 181, 126, 277, 148, 174, 201, 397, 225, 255, 287, 318, 348, 547, 382, 733, 417, 456, 496, 535, 576, 947, 621, 666, 711, 1213, 758, 1499, 805, 858, 910, 1831, 963, 1020, 1078, 1137, 1195, 2207, 1255 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`a(n) is prime iff n is prime.`
	FORMULA	`For n prime, a(n) = p(A034387(n)-n+1). For n composite, a(n) = A002808([n*(n+1)/2]-A034387(n)-n).`
	CROSSREFS	`Cf. A084408, A084409, A084411.` `Sequence in context: A121274 A111681 A073122 * A080067 A117824 A122212` `Adjacent sequences: A084407 A084408 A084409 * A084411 A084412 A084413`
	KEYWORD	`nonn,easy`
	AUTHOR	`Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jun 01 2003`
	EXTENSIONS	`Edited and extended by David Wasserman (wasserma(AT)spawar.navy.mil), Dec 27 2004`

Content is available under The OEIS End-User License Agreement .

Last modified February 16 10:43 EST 2012. Contains 205904 sequences.