A081652 Greatest common divisor of n and sum of decimal digits of n-th prime.

1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 7, 1, 8, 1, 1, 1, 4, 1, 2, 1, 1, 1, 2, 1, 4, 1, 5, 1, 1, 11, 1, 7, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 11, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 8, 1, 1, 1, 4, 1, 2, 1, 8, 1, 2, 1, 10, 1, 17, 1, 4

Offset

1,6

Links

Table of n, a(n) for n=1..104.

Formula

a(n) = GCD(n, A007605(n)).

Example

a(16) = GCD(16, A007953(A000040(16))) = GCD(16, A007953(53)) = GCD(16,5+3) = GCD(8*2,8) = 8.

Mathematica

Table[GCD[n, Total[IntegerDigits[Prime[n]]]], {n, 110}] (* Harvey P. Dale, Jul 12 2012 *)

Crossrefs

Cf. A000040, A007953, A081653, A066750.

Sequence in context: A329349 A329348 A329344 * A302790 A363455 A333849

Adjacent sequences: A081649 A081650 A081651 * A081653 A081654 A081655

Keyword

nonn,base,easy

Author

Reinhard Zumkeller, Mar 25 2003

Status

approved