A185015 - OEIS

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A185015

Characteristic function of 5.

17

0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

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OFFSET

0,1

COMMENTS

Number of connected 2-regular (simple) graphs with girth exactly 5.

The Euler transformation of this sequence is A079998.

LINKS

Table of n, a(n) for n=0..85.

Index entries for linear recurrences with constant coefficients, signature (1).

FORMULA

a(n) = A185115(n) - A185116(n).

PROG

(Python)

def A185015(n): return int(n==5) # Chai Wah Wu, Feb 04 2022

CROSSREFS

Characteristic function of g: A000007 (g=0), A063524 (g=1), A185012 (g=2), A185013 (g=3), A185014 (g=4), this sequence (g=5), A185016 (g=6), A185017 (g=7).

Sequence in context: A011678 A011679 A011682 * A318880 A177063 A341619

Adjacent sequences: A185012 A185013 A185014 * A185016 A185017 A185018

KEYWORD

nonn,easy

AUTHOR

Jason Kimberley, Sep 30 2011

STATUS

approved