A055233 - OEIS

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A055233

Composite numbers equal to the sum of the primes from their smallest prime factor to their largest prime factor.

10, 39, 155, 371, 2935561623745, 454539357304421 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	COMMENTS	`Composite n such that n = p_1 + p_2 + ... + p_k where the p_i are consecutive primes, p_1 is the smallest prime factor of n and p_k is the largest.`
	LINKS	`Erich Friedman, What's Special About This Number?` `C. Rivera, Puzzle` `Robert Munafo, Notable Properties of Specific Numbers`
	EXAMPLE	`10 = 25 = 2 + 3 + 5; 39 = 313 = 3 + 5 + 7 + 11 + 13; 371 = 7*53 = 7 + 11 + 13 + ... + 53.`
	CROSSREFS	`Cf. A074036, A055514, A169802.` `Sequence in context: A059722 A074225 A055514 * A189947 A197705 A187205` `Adjacent sequences: A055230 A055231 A055232 * A055234 A055235 A055236`
	KEYWORD	`nice,nonn`
	AUTHOR	`Carlos B. Rivera F (crivera(AT)primepuzzles.net), Jun 21 2000`
	EXTENSIONS	`a(5) found by Jud McCranie (JudMcCranie(AT)ugaalum.uga.edu), Jul 03 2000` `Concerning a(6): 454539357304421 is the product of two primes, 3536123 * 128541727 and also the sum of these two plus all the primes in between: 3536123 + 3536129 + 3536131 + ... + 128541719 + 128541727. I do not know if there are any terms in A055233 between 2935561623745 and 454539357304421. (I have searched for values of N satisfying N=PaPb=Pa+...+Pb as far as 5.9810^16, but this is not quite the same as A0055233 or A055514.) - Robert P. Munafo (mrob(AT)mrob.com), Nov 20 2002` `454539357304421 confirmed to be the 6th term by Donovan Johnson (donovan.johnson(AT)yahoo.com), Aug 23 2010` `Example: removed last (see A055514). - Manuel Valdivia, Nov 19 2011`

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Last modified February 23 02:42 EST 2012. Contains 206606 sequences.