A191000 Greedy inverse of A034690: the smallest number m such that sum of digits of all divisors of m equals n; a(n) = 0 if no such number exists.

1, 0, 2, 3, 13, 5, 4, 7, 10, 0, 19, 6, 9, 21, 8, 403, 79, 34, 12, 39, 35, 16, 129, 38, 133, 52, 30, 100, 28, 18, 81, 63, 24, 75, 333, 66, 64, 117, 99, 243, 76, 60, 889, 171, 88, 36, 279, 54, 484, 387, 78, 48, 475, 136, 1209, 208, 132, 729, 112, 258, 225, 84, 90, 399, 1396, 162, 741, 796

Offset

1,3

Links

Michel Marcus, Table of n, a(n) for n = 1..2000

Example

a(5) = 13 because 13 is the smallest number such that sum of digits of all its divisors is equal to 5: 1 + 1 + 3 = 5.
a(2) = a(10) = 0 because there is no number such that sum of digits of all its divisors is equal to 2 or 10.

Prog

(PARI) sdd(n) = sumdiv(n, d, sumdigits(d)); \\ A034690
a(n) = if ((n==2) || (n==10), return (0)); my(k=1); while (sdd(k) != n, k++); k; \\ Michel Marcus, Oct 06 2021

Crossrefs

Cf. A034690.

Sequence in context: A067180 A067182 A342667 * A361831 A085402 A085400

Adjacent sequences: A190997 A190998 A190999 * A191001 A191002 A191003

Keyword

nonn,base

Author

Jaroslav Krizek, Jun 15 2011

Status

approved