A028553 - OEIS

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A028553

Numbers n such that n(n+3) is a palindrome.

0, 1, 8, 28, 66, 88, 211, 298, 671, 2126, 2998, 28814, 29369, 29998, 63701, 212206, 212671, 299998, 636776, 2122206, 2861419, 2999998, 9443423, 21341691, 28862883, 29999998, 212325206, 289053683, 294127328, 294174669, 299999998 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,3`
	COMMENTS	`Also: sum of the first n even composites is palindromic. Sequence is 4 + 6 + 8 + 10 + 12 + 14 + ... + z. For values of z see A058851. (Comment added by author 12/2000).`
	LINKS	`Table of n, a(n) for n=1..31.` `P. De Geest, Palindromic Quasipronics` `P. De Geest, Palindromic Sums 2` `Erich Friedman, What's Special About This Number? (See entries 298, 2126, 2998.)`
	CROSSREFS	`Cf. A058852, A028554.` `Sequence in context: A007259 A134747 A083013 * A100182 A321237 A328535` `Adjacent sequences: A028550 A028551 A028552 * A028554 A028555 A028556`
	KEYWORD	`nonn,base`
	AUTHOR	`Patrick De Geest`
	STATUS	`approved`

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Last modified January 21 11:11 EST 2020. Contains 331105 sequences. (Running on oeis4.)