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A086047 Sum of first n 5-almost primes. 3
32, 80, 152, 232, 340, 452, 572, 734, 902, 1078, 1258, 1458, 1666, 1909, 2161, 2425, 2695, 2967, 3247, 3547, 3851, 4163, 4531, 4909, 5301, 5697, 6102, 6510, 6930, 7370, 7820, 8276, 8740, 9208, 9704, 10204, 10724, 11276, 11843, 12431, 13023, 13617 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Elements in this sequence can themselves be 5-almost primes. a(1) = 32 = 2^5. a(2) = 80 = 2^4 * 5. a(27) = 6102 = 2 * 3^3 * 113 a(28) = 6510 = 2 * 3 * 5 * 7 * 31 a(31) = 7820 = 2^2 * 5 * 17 * 23 a(33) = 8740 = 2^2 * 5 * 19 * 23. Does this happen infinitely often? - Jonathan Vos Post, Dec 11 2004

LINKS

Table of n, a(n) for n=1..42.

EXAMPLE

a(2)=80 because sum of first two 5-almost primes, i.e. 32+48, is 80.

MATHEMATICA

Accumulate[Select[Range[1000], PrimeOmega[#]==5&]] (* Harvey P. Dale, Jan 19 2018 *)

CROSSREFS

Sequence in context: A240054 A135269 A234140 * A209378 A182466 A234133

Adjacent sequences:  A086044 A086045 A086046 * A086048 A086049 A086050

KEYWORD

easy,nonn

AUTHOR

Shyam Sunder Gupta, Aug 24 2003

STATUS

approved

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Last modified August 22 07:17 EDT 2019. Contains 326172 sequences. (Running on oeis4.)