A236186 - OEIS

A236186

Differences between terms of compacting Eratosthenes sieve for prime(5) = 11.

2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 6, 6, 2, 6, 4, 2, 6, 4, 6, 8, 4, 2, 4, 2, 4, 8, 6, 4, 6, 2, 4, 6, 2, 6, 6, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 10, 2, 10, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 6, 6, 2, 6, 4, 2, 6, 4, 6, 8, 4, 2, 4, 2, 4, 8, 6, 4, 6, 2, 4, 6, 2, 6, 6, 4, 2, 4

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OFFSET

1,1

COMMENTS

P(x) is a function which represents a prime number at a particular ordinal x. This pattern, dp(x), describes the difference between consecutive prime numbers as described by p(x) (see A236175) and therefore the length of dp(x) is len(p(x)) - 1 and each value in dp(x) times P(x) is the difference between values determined not primed when running one pass of a reductive sieve, starting at P(x)^2. See A236185.

LINKS

Table of n, a(n) for n=1..86.

FORMULA

a(n + 48) = a(n). - Michael Somos, Mar 10 2014

PROG

(PARI) {a(n) = my(A); if( n<1, 0, A = vector( n*50 + 148, k, k+1); for( i = 1, 4, A = select( k -> k%prime(i), A) ); polcoeff( (1 - x) * Ser( select( k -> k>11 && (k%11) == 0, A) / 11), n))}; /* Michael Somos, Mar 10 2014 */

CROSSREFS

Cf. A236175-A236180, A236185-A236190.

Sequence in context: A300448 A214781 A214850 * A143271 A267654 A128859

Adjacent sequences: A236183 A236184 A236185 * A236187 A236188 A236189

KEYWORD

nonn

AUTHOR

Christopher J. Hanson, Jan 21 2014

EXTENSIONS

Made sequence periodic. - Michael Somos, Mar 10 2014

STATUS

approved