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A114145 Self-describing sequence : 2 composite integers between two primes, then 4 composites, then 6, then 7, then 8, etc. The quantity of composites in each run is given by the sequence itself. (Sequence is strictly increasing and the smallest next available prime is used when needed). 0
2, 4, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 18, 20, 21, 23, 24, 25, 26, 27, 28, 30, 32, 37, 38, 39, 40, 42, 44, 45, 46, 48, 53, 54, 55, 56, 57, 58, 60, 62, 63, 64, 67, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 83, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 102 (list; graph; refs; listen; history; internal format)
OFFSET

2,1

COMMENTS

PARI program by Klaus Brockhaus.

EXAMPLE

Runs of composites between brackets:

2,(4,6),7,(8,9,10,12),13,(14,15,16,18,20,21),23,(24,25,26,27,28,30,32)...

.^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^

.2 comp. 4 comp. 6 comp. 7 comp. (etc.) = the sequence itself

PROG

(PARI) {m=20; k=2; v=[k]; for(j=1, m, count=0; while(count<v[j], if(!isprime(k), v=concat(v, k); count++); k++); k=nextprime(k); v=concat(v, k)); for(n=1, #v, print1(v[n], ", "))}

CROSSREFS

Sequence in context: A015860 A147613 A155939 * A153351 A153343 A136499

Adjacent sequences:  A114142 A114143 A114144 * A114146 A114147 A114148

KEYWORD

base,easy,nonn

AUTHOR

Eric Angelini (eric.angelini(AT)kntv.be), Feb 03 2006

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Last modified February 17 20:50 EST 2012. Contains 206085 sequences.