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A086059 Sum of first n 7-almost primes. 0
128, 320, 608, 928, 1360, 1808, 2288, 2936, 3608, 4312, 5032, 5832, 6664, 7636, 8644, 9700, 10780, 11868, 12988, 14188, 15404, 16652, 18110, 19582, 21094, 22662, 24246, 25866, 27498, 29178, 30938, 32738, 34562, 36418, 38290, 40274, 42274, 44354 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Elements in this sequence can themselves be 7-almost primes. a(1) = 128 = 2^7. Also a 7-Brilliant number. a(2) = 320 = 2^6 * 5. Also a 7-Brilliant number. Does this happen infinitely often? - Jonathan Vos Post, Dec 11 2004

LINKS

Table of n, a(n) for n=1..38.

EXAMPLE

a(2)=320 because sum of first two 7-almost primes i.e. 128+192 is 320.

MATHEMATICA

Accumulate[Select[Range[2500], PrimeOmega[#]==7&]] (* Harvey P. Dale, Oct 18 2018 *)

CROSSREFS

Sequence in context: A045053 A234877 A229360 * A220582 A203449 A195090

Adjacent sequences:  A086056 A086057 A086058 * A086060 A086061 A086062

KEYWORD

easy,nonn

AUTHOR

Shyam Sunder Gupta, Aug 24 2003

STATUS

approved

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Last modified October 16 13:24 EDT 2019. Contains 328084 sequences. (Running on oeis4.)