login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A077650 Initial digits of sigma[n], the sum of divisors of n. 0
1, 3, 4, 7, 6, 1, 8, 1, 1, 1, 1, 2, 1, 2, 2, 3, 1, 3, 2, 4, 3, 3, 2, 6, 3, 4, 4, 5, 3, 7, 3, 6, 4, 5, 4, 9, 3, 6, 5, 9, 4, 9, 4, 8, 7, 7, 4, 1, 5, 9, 7, 9, 5, 1, 7, 1, 8, 9, 6, 1, 6, 9, 1, 1, 8, 1, 6, 1, 9, 1, 7, 1, 7, 1, 1, 1, 9, 1, 8, 1, 1, 1, 8, 2, 1, 1, 1, 1, 9, 2, 1, 1, 1, 1, 1, 2, 9, 1, 1, 2, 1, 2, 1, 2, 1 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

FORMULA

a[n]=A000030[A000203(n)]

MATHEMATICA

Table[First[IntegerDigits[DivisorSigma[1, w]]], {w, 1, 128}]

CROSSREFS

Cf. A000030, A000203.

Sequence in context: A082226 A010613 A134688 * A105853 A017665 A105852

Adjacent sequences:  A077647 A077648 A077649 * A077651 A077652 A077653

KEYWORD

base,nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Nov 19 2002

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 03:45 EST 2012. Contains 205978 sequences.