login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A286891 Initial primes of 6 consecutive primes with 5 consecutive gaps 10, 8, 6, 4, 2. 3
41203, 556243, 576193, 715849, 752263, 859249, 891799, 1107763, 1191079, 1201999, 1210369, 1510189, 1601599, 1893163, 2530963, 2678719, 2881243, 3257689, 3431479, 3545263, 3792949, 3804919, 4041109, 4479463, 4867309 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms = {13,19} mod 30.

For initial primes of 6 consecutive primes with consecutive gaps 2, 4, 6, 8, 10 see A190817.

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

R. J. Mathar, Table of Prime Gap Constellations

EXAMPLE

Prime(4313..4318) = {41203, 41213, 41221, 41227, 41231, 41233} and 41203 + 10 = 41213, 41213 + 8 = 41221, 41221 + 6 = 41227, 41227 + 4 = 41231, 41231 + 2 = 41233.

Also, prime(68287..68292) = {859249, 859259, 859267, 859273, 859277, 859279} and 859249 + 10 = 859259, 859259 + 8 = 859267, 859267 + 6 = 859273, 859273 + 4 = 859277, 859277 + 2 = 859279.

MAPLE

K:=10^7: # to get all terms <= K.

Primes:=select(isprime, [seq(i, i=3..K+30, 2)]): Primes[select(t->[Primes[t+1]-Primes[t], Primes[t+2]-Primes[t+1], Primes[t+3]-Primes[t+2], Primes[t+4]-Primes[t+3], Primes[t+5]-Primes[t+4]]=[10, 8, 6, 4, 2], [$1..nops(Primes)-5])]; # Muniru A Asiru, Aug 15 2017

MATHEMATICA

Select[Partition[Prime[Range[340000]], 6, 1], Differences[#]=={10, 8, 6, 4, 2}&][[All, 1]] (* Harvey P. Dale, Aug 22 2018 *)

PROG

(GAP)

P:=Filtered([1..20000000], IsPrime);;  I:=Reversed([2, 4, 6, 8, 10]);;

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

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

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

CROSSREFS

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

Sequence in context: A257422 A257429 A254238 * A183667 A188488 A027577

Adjacent sequences:  A286888 A286889 A286890 * A286892 A286893 A286894

KEYWORD

nonn

AUTHOR

Muniru A Asiru, Jul 22 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 20 02:46 EDT 2019. Contains 322291 sequences. (Running on oeis4.)