A325454 a(n) is the digit sum of the n-th Niven number (or Harshad number).

1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 3, 9, 2, 3, 6, 9, 3, 9, 4, 6, 9, 12, 5, 9, 6, 9, 7, 9, 8, 9, 12, 9, 1, 3, 9, 2, 3, 4, 6, 9, 3, 9, 6, 7, 9, 5, 9, 6, 8, 9, 12, 9, 9, 9, 10, 12, 15, 18, 2, 3, 6, 9, 11, 3, 9, 4, 6, 8, 9, 12, 5, 9, 6, 9, 13, 9, 9, 12, 14, 9, 10, 15

Offset

1,2

Links

Table of n, a(n) for n=1..82.

Formula

a(n) = A005349(n)/A113315(n).

a(n) = A007953(A005349(n)).

Prog

(PARI) is_a005349(n) = n%sumdigits(n)==0
terms(n) = my(i=0); for(k=1, oo, if(i>=n, break); if(is_a005349(k), print1(sumdigits(k), ", "); i++))
terms(80) \\ Print initial 80 terms

Crossrefs

Cf. A005349, A007953, A113315.

Sequence in context: A061486 A264600 A138470 * A112875 A113018 A113009

Adjacent sequences: A325451 A325452 A325453 * A325455 A325456 A325457

Keyword

nonn,base,easy

Author

Felix Fröhlich, Sep 06 2019

Status

approved