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A257560 First differences of A257559. 1
2, 3, 5, 7, 12, 13, 16, 20, 24, 27, 28, 33, 41, 43, 45, 48, 51, 56, 57, 62, 65, 69, 71, 76, 77, 82, 84, 86, 87, 88, 91, 92, 93, 96, 97, 103, 105, 106, 114, 116, 118, 125, 133, 135, 137, 140, 143, 147, 149, 155, 158, 162, 165, 167, 172, 176, 177, 183 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

By definition this sequence is strictly increasing. Heuristically a(n) is around 2n log n/log log n. - Charles R Greathouse IV, May 01 2015

LINKS

Zak Seidov, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = A257559(n+1) - A257559(n).

PROG

(PARI) issemi(n)=bigomega(n)==2

t=0; v=List(); last=4; while(1, n=last+t; while(!issemi(n++), ); listput(v, t=n-last); if(v==100, return(Set(v))); last=n) \\ Charles R Greathouse IV, May 01 2015

CROSSREFS

Cf. A257559.

Sequence in context: A260181 A140971 A073689 * A187774 A031216 A004683

Adjacent sequences:  A257557 A257558 A257559 * A257561 A257562 A257563

KEYWORD

nonn

AUTHOR

Zak Seidov, Apr 30 2015

STATUS

approved

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Last modified May 11 09:11 EDT 2021. Contains 343788 sequences. (Running on oeis4.)