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A244621 (First arithmetic derivative of primorials) read mod 12. 1
1, 5, 7, 7, 11, 5, 7, 7, 11, 1, 1, 7, 5, 5, 1, 11, 7, 1, 1, 5, 11, 11, 7, 5, 11, 1, 1, 5, 11, 1, 1, 5, 7, 7, 5, 5, 11, 11, 7, 5, 1, 7, 11, 5, 7, 7, 7, 7, 11, 5, 7, 11, 5, 1, 11, 7, 5, 5, 11, 1, 1, 11, 11, 7, 1, 11, 11, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A024451 as numerator of Sum_{i = 1..n} 1/prime(i) is the first arithmetic derivative of primorials prime(n)# of A002110. a(n) shows the distribution of A024451 over four residual classes.

LINKS

Table of n, a(n) for n=1..68.

FORMULA

a(n) = (prime(n)#)' mod 12 or a(n) = A024451(n) mod 12.

EXAMPLE

a(4) = [(prime(4)#)' = (4#)' = (210)' = 247] mod 12 = 7,

a(6) = [(prime(6)#)' = (13#)' = (30030)' = 40361] mod 12 = 5.

PROG

(PARI) a(n) = numerator(sum(i=1, n, 1/prime(i))) % 12; \\ Michel Marcus, Jul 07 2014

CROSSREFS

Cf. A002110, A024451, A003415, A244622.

Sequence in context: A264527 A137755 A258316 * A201459 A053672 A087525

Adjacent sequences:  A244618 A244619 A244620 * A244622 A244623 A244624

KEYWORD

nonn

AUTHOR

Freimut Marschner, Jul 02 2014

STATUS

approved

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Last modified October 18 03:25 EDT 2019. Contains 328135 sequences. (Running on oeis4.)