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A269389 Numbers n for which prime(n+7)-prime(n+6) is not a multiple of three. 7
1, 2, 4, 6, 7, 8, 11, 13, 14, 16, 18, 19, 20, 21, 22, 23, 24, 25, 27, 28, 29, 32, 35, 36, 37, 38, 39, 42, 43, 44, 46, 47, 51, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 66, 69, 71, 72, 73, 74, 75, 76, 77, 79, 81, 82, 83, 84, 86, 87, 88, 89, 92, 95, 98, 100, 103, 106, 107, 109, 110, 111, 114, 116, 118, 119, 120, 121, 122, 125 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A270189(6+n) - 6.

Other identities. For all n >= 1:

A269362(a(n)) = n.

MATHEMATICA

Select[Range@ 125, ! Divisible[Prime[# + 7] - Prime[# + 6], 3] &] (* Michael De Vlieger, Mar 18 2016 *)

Drop[Flatten[Position[Partition[Prime[Range[200]], 2, 1], _?(Mod[#[[2]]- #[[1]], 3]!=0&), 1, Heads->False]], 6]-6 (* Harvey P. Dale, Dec 17 2018 *)

PROG

(Scheme, with Antti Karttunen's IntSeq-library)

(define A269389 (MATCHING-POS 1 1 (lambda (n) (< 0 (A137264 (+ 6 n))))))

(PARI) isok(n) = ((prime(n+7) - prime(n+6)) % 3) != 0; \\ Michel Marcus, Mar 18 2016

CROSSREFS

Complement: A269399.

Left inverse: A269362.

Cf. A270189.

Cf. also A270199.

Sequence in context: A139527 A163578 A345918 * A092054 A334573 A228370

Adjacent sequences:  A269386 A269387 A269388 * A269390 A269391 A269392

KEYWORD

nonn

AUTHOR

Antti Karttunen, Mar 16 2016

STATUS

approved

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Last modified July 29 06:21 EDT 2021. Contains 346340 sequences. (Running on oeis4.)