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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
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.
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);
KEYWORD
nonn
AUTHOR
Muniru A Asiru, Jul 25 2017
EXTENSIONS
a(6)-a(21) from Giovanni Resta, Jul 25 2017
STATUS
approved