

A114407


7almost prime gaps. First differences of A046308.


2



64, 96, 32, 112, 16, 32, 168, 24, 32, 16, 80, 32, 140, 36, 48, 24, 8, 32, 80, 16, 32, 210, 14, 40, 56, 16, 36, 12, 48, 80, 40, 24, 32, 16, 112, 16, 80, 107, 21, 60, 84, 16, 8, 54, 18, 16, 56, 104, 16, 60, 20, 16, 16, 32, 16, 8, 104, 64, 24, 8, 32, 80, 192, 80, 10, 126, 24, 12
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS

Zak Seidov, Table of n, a(n) for n = 1..10000


FORMULA

a(n) = A046308(n+1)  A046308(n).


EXAMPLE

a(1) = 64 = 192128 where 128 is the first 7almost prime and 192 is the second.
a(2) = 96 = 288192.
a(3) = 32 = 320288.
a(4) = 112 = 432320.
a(5) = 16 = 448432.
a(6) = 32 = 480448.
a(7) = 168 = 648480.
a(8) = 24 = 672648.


MATHEMATICA

Differences[Select[Range[10000], PrimeOmega[#]==7&]] (* Harvey P. Dale, Oct 13 2019 *)


CROSSREFS

Cf. A046308, A065516, A111870, A111871, A114403A114411, A114412A114422.
Sequence in context: A240527 A262743 A176819 * A259942 A114417 A046305
Adjacent sequences: A114404 A114405 A114406 * A114408 A114409 A114410


KEYWORD

easy,nonn


AUTHOR

Jonathan Vos Post, Nov 25 2005


EXTENSIONS

Corrected and extended by R. J. Mathar, Aug 31 2007


STATUS

approved



