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A154891 Where records occurs in A154804. 0
1, 2, 4, 9, 12, 21, 24, 30, 42, 45, 57, 60, 75, 84, 90, 105, 135, 150, 165, 195, 210, 255, 315, 330, 390, 420, 525, 630, 735, 825, 840, 945, 1050, 1155, 1365, 1575, 1680, 1785, 1995, 2100, 2145, 2205, 2310, 2625, 2730, 3045, 3255, 3465, 3990 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..49.

MAPLE

A008578 := proc(n) RETURN( n=1 or isprime(n) ) ; end : A154804 := proc(n) local a, d; a := 0 ; for d from 1 to n-1 do if A008578(n-d) and A008578(n+d) then a := a+1; fi; od: a ; end: a804 := [seq(A154804(n), n=1..4000)] ; r := RECORDS(a804)[2] ; # R. J. Mathar, Mar 14 2009

CROSSREFS

Cf. A008578, A154804, A154720, A154721, A154799.

Sequence in context: A111302 A241200 A092530 * A282456 A176472 A139557

Adjacent sequences:  A154888 A154889 A154890 * A154892 A154893 A154894

KEYWORD

nonn

AUTHOR

Omar E. Pol, Feb 01 2009

EXTENSIONS

More terms from R. J. Mathar, Mar 14 2009

STATUS

approved

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Last modified October 16 16:18 EDT 2019. Contains 328101 sequences. (Running on oeis4.)