A067342 Sum of decimal digits of sum of divisors of n.

1, 3, 4, 7, 6, 3, 8, 6, 4, 9, 3, 10, 5, 6, 6, 4, 9, 12, 2, 6, 5, 9, 6, 6, 4, 6, 4, 11, 3, 9, 5, 9, 12, 9, 12, 10, 11, 6, 11, 9, 6, 15, 8, 12, 15, 9, 12, 7, 12, 12, 9, 17, 9, 3, 9, 3, 8, 9, 6, 15, 8, 15, 5, 10, 12, 9, 14, 9, 15, 9, 9, 15, 11, 6, 7, 5, 15, 15, 8, 15, 4, 9, 12, 8, 9, 6, 3, 9, 9, 9

Offset: 1

Author

Labos Elemer, Jan 16 2002

Keywords

• nonn
• base

Examples

			n=100, sigma(100)=217, SumDigit(217)=10, a(100)=10.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000
• Index entries for sequences related to sigma(n)

Crossrefs

Cf. A000203, A007953, A077650, A175548.

Programs

Mathematica

Array[Total[IntegerDigits[DivisorSigma[1,#]]]&,90] (* Harvey P. Dale, Jan 02 2012 *)

PARI

vector(80, n, sumdigits(sigma(n))) \\ Michel Marcus, Apr 08 2015

Formula

a(n) = A007953(A000203(n)). - Michel Marcus, Dec 26 2013

Extensions

Offset corrected to 1 by Michel Marcus, Dec 26 2013