id:A117511 - OEIS Search Results

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Triangular numbers for which the sum of the digits equals the sum of the digits of the next triangular number.

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36, 153, 2556, 3240, 4851, 5778, 9045, 11628, 13041, 14706, 17766, 19503, 33930, 41328, 46665, 49455, 52326, 71253, 74691, 81810, 85491, 93096, 109278, 122265, 131328, 140715, 145530, 160461, 170820, 181503, 192510, 203841, 252405, 258840 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`s(n) stands for the sum of the digits of n. Each number of the sequence is divisible by 9.`
	FORMULA	`s(a(n))=s(a(n+1))`
	EXAMPLE	`153 is in the sequence because (1) 153 is triangular number a(18), triangular number a(19)=171 and (2) 1+5+3=1+7+1`
	CROSSREFS	`Cf. A000217.` `Sequence in context: A039495 A034592 A160754 this_sequence A064244 A064500 A017054` `Adjacent sequences: A117508 A117509 A117510 this_sequence A117512 A117513 A117514`
	KEYWORD	`base,nonn`
	AUTHOR	`Luc Stevens (lms022(AT)yahoo.com), Apr 26 2006`

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Last modified November 24 14:25 EST 2009. Contains 167438 sequences.

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