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A078705 Integer part of the square root of sigma(n). 2
1, 1, 2, 2, 2, 3, 2, 3, 3, 4, 3, 5, 3, 4, 4, 5, 4, 6, 4, 6, 5, 6, 4, 7, 5, 6, 6, 7, 5, 8, 5, 7, 6, 7, 6, 9, 6, 7, 7, 9, 6, 9, 6, 9, 8, 8, 6, 11, 7, 9, 8, 9, 7, 10, 8, 10, 8, 9, 7, 12, 7, 9, 10, 11, 9, 12, 8, 11, 9, 12, 8, 13, 8, 10, 11, 11, 9, 12, 8, 13, 11, 11, 9, 14, 10, 11, 10, 13, 9, 15, 10, 12, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
FORMULA
a(n) = A000196(A000203(n)). - Antti Karttunen, Nov 18 2017
MATHEMATICA
Table[Floor[Sqrt[DivisorSigma[1, i]]], {i, 1, 100}]
PROG
(Scheme) (define (A078705 n) (A000196 (A000203 n))) ;; [For the implementations of A000196 and A000203, see under the respective entries]. - Antti Karttunen, Nov 18 2017
(PARI) a(n) = sqrtint(sigma(n)); \\ Michel Marcus, Nov 18 2017
CROSSREFS
Sequence in context: A366066 A352627 A182210 * A346018 A050331 A259194
KEYWORD
easy,nonn,look
AUTHOR
Joseph L. Pe, Dec 18 2002
STATUS
approved

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Last modified April 22 09:25 EDT 2024. Contains 371894 sequences. (Running on oeis4.)