id:A061885 - OEIS Search Results

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n + largest triangular number less than or equal to n.

+0
3

0, 2, 3, 6, 7, 8, 12, 13, 14, 15, 20, 21, 22, 23, 24, 30, 31, 32, 33, 34, 35, 42, 43, 44, 45, 46, 47, 48, 56, 57, 58, 59, 60, 61, 62, 63, 72, 73, 74, 75, 76, 77, 78, 79, 80, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 132 (list; graph; listen)

	OFFSET	`0,2`
	COMMENT	`a(9)=9+6=15; a(10)=10+10=20; a(11)=11+10=21.`
	FORMULA	`a(n) = n+A057944(n) = 2n-A002262(n) = n+[(sqrt(1+8n)-1)/2][(sqrt(1+8*n)+1)/2]/2.`
	CROSSREFS	`Cf. A060985.` `Sequence in context: A069579 A065193 A116047 this_sequence A138683 A072426 A127330` `Adjacent sequences: A061882 A061883 A061884 this_sequence A061886 A061887 A061888`
	KEYWORD	`nonn`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), May 12 2001`

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Last modified July 25 07:41 EDT 2008. Contains 142293 sequences.

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