login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A337197 Position of the first occurrence of n in A337196, where A337196(x) is the 3-adic valuation of 1+A000265(sigma(x)). 1
1, 19, 67, 211, 643, 3667, 5827, 17491, 104971, 628123, 1795063, 2759719, 4251523, 12754579, 83086924 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(16) = 393475036, but a(15) is a larger than that, thus the sequence is nonmonotonic.

LINKS

Table of n, a(n) for n=0..14.

FORMULA

For all n >= 0, A337196(a(n)) = n, with no n occurring in A337196 before a(n).

MATHEMATICA

With[{s = Array[IntegerExponent[1 + #/2^IntegerExponent[#, 2], 3] &@ DivisorSigma[1, #] &, 10^6]}, Array[FirstPosition[s, #][[1]] &, Max[s] + 1, 0]] (* Michael De Vlieger, Feb 22 2021 *)

CROSSREFS

Cf. A004394, A337196.

Cf. also A200849.

Sequence in context: A165806 A142404 A139927 * A228670 A044157 A044538

Adjacent sequences:  A337194 A337195 A337196 * A337198 A337199 A337200

KEYWORD

nonn,more

AUTHOR

Antti Karttunen and David A. Corneth, Aug 18 2020

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 27 00:02 EDT 2021. Contains 348270 sequences. (Running on oeis4.)