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A290264 Initial primes of 9 consecutive primes with 8 consecutive gaps 16, 14, 12, 10, 8, 6, 4, 2. 0
32465047, 37091581, 146742847, 239659891, 245333251, 272213797, 1060690651, 1541736811, 2002738207, 2480351677, 2636566351, 4421955007, 6168859201, 8158683037, 10367633527, 10623394321, 11452116817, 11691059641, 11892876841, 13551877831, 15043908637 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms = {1,7} mod 30.

For initial primes of 7 consecutive primes with 6 consecutive gaps 12, 10, 8, 6, 4, 2 and 8 consecutive primes with 7 consecutive gaps 14, 12, 10, 8, 6, 4, 2 see A290161 and A290162 respectively.

a(6) > 250000000.

LINKS

Table of n, a(n) for n=1..21.

EXAMPLE

32465047 is a member of this sequence because the 9 consecutive primes 32465047, 32465063, 32465077, 32465089, 32465099, 32465107, 32465113, 32465117, 32465119 have consecutive gaps 16, 14, 12, 10, 8, 6, 4, 2. That is, 32465047 + 16 = 32465063, 32465063 + 14 = 32465077, 32465077 + 12 = 32465089, 32465089 + 10 = 32465099, 32465099 + 8 = 32465107, 32465107 + 6 = 32465113, 32465113 + 4 = 32465117, 32465117 + 2 = 32465119.

PROG

(GAP)

P:=Filtered([1..50000000], IsPrime);; I:=Reversed([2, 4, 6, 8, 10, 12, 14, 16]);;

P1:=List([1..Length(P)-1], i->P[i+1]-P[i]);;  Collected(last);;

P2:=List([1..Length(P)-Length(I)], i->[P1[i], P1[i+1], P1[i+2], P1[i+3], P1[i+4], P1[i+5], P1[i+6], P1[i+7]]);;

P3:=List(Positions(P2, I), i->P[i]); Length(P3);

CROSSREFS

Cf. A078847, A190814, A190817, A190819, A190838, A290161, A290162.

Sequence in context: A252356 A153752 A209912 * A206043 A157080 A157081

Adjacent sequences:  A290261 A290262 A290263 * A290265 A290266 A290267

KEYWORD

nonn

AUTHOR

Muniru A Asiru, Jul 25 2017

EXTENSIONS

a(6)-a(21) from Giovanni Resta, Jul 25 2017

STATUS

approved

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Last modified August 3 10:43 EDT 2021. Contains 346435 sequences. (Running on oeis4.)