A098515 - OEIS

This site is supported by donations to The OEIS Foundation.

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.

Other ways to donate

A098515

Least m such that m and m+n are both products of exactly n primes counting multiplicity.

1, 2, 4, 27, 36, 675, 810, 12393, 7552, 268992, 506240, 6436341, 2440692, 290698227, 455503986, 4897228800, 520575984, 519417147375, 124730265582, 8961777270765, 753891573760, 203558860750848, 51126160064490, 4021771417157632, 1305269217263592, 69131417822953472, 57710779788427264, 1838459534098563045, 63846774162325476 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,2`
	LINKS	`Table of n, a(n) for n=1..29.`
	EXAMPLE	`4=22 & 6=23; 27=333 & 30=235; 36=2233 & 40=2225; 675=33355 & 680=222517; 810=233335 and 816=2222317; etc.`
	MATHEMATICA	`f[n_Integer] := Plus @@ Transpose[FactorInteger[n]][[2]]; g[n_] := (k = 2^n; While[a = f[k]; b = f[k + n]; a != b \|\| a != n, k++ ]; k); Do[ Print[ g[n]], {n, 12}]`
	CROSSREFS	`Cf. A097978.` `Cf. A097978, A135058.` `Sequence in context: A095182 A104465 A175759 * A256451 A059719 A264930` `Adjacent sequences: A098512 A098513 A098514 * A098516 A098517 A098518`
	KEYWORD	`nonn`
	AUTHOR	`Robert G. Wilson v, Sep 11 2004`
	EXTENSIONS	`More terms from David Wasserman, Feb 20 2008`
	STATUS	`approved`

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 10 20:48 EST 2019. Contains 329909 sequences. (Running on oeis4.)