A069661 Smallest n-digit prime with maximum digit sum.

7, 89, 997, 8999, 98999, 989999, 9899999, 89999999, 998999999, 9899989999, 98999999999, 999998999999, 8998999999999, 99899999999999, 999999899999999, 9998999999999999, 99999999999899999, 999998999999999999, 9998999999999999999, 89999999999999999999

Offset

1,1

Links

Table of n, a(n) for n=1..20.

Mathematica

Table[max=0; Do[p=Prime[i]; If[Total[IntegerDigits[p]] > Total[IntegerDigits[max]], max=p], {i, PrimePi[10^n]+1, PrimePi[10^(n+1)]}]; max, {n, 0, 7}] (* Jayanta Basu, May 19 2013 *)

Crossrefs

a(n) = A069662(n) for these n <= 20: 1, 2, 3, 4, 6, 7, 9, 17 and 19. a(5) = Reverse(A069662(5)).

Sequence in context: A107109 A089771 A249448 * A069662 A359646 A371386

Adjacent sequences: A069658 A069659 A069660 * A069662 A069663 A069664

Keyword

nonn,base

Author

Amarnath Murthy, Apr 05 2002

Extensions

Corrected and extended by Rick L. Shepherd, Jul 15 2002. a(5) through a(20) have been certified prime with Primo.

Status

approved