This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A037225 a(n) = phi(2n+1). 14
 1, 2, 4, 6, 6, 10, 12, 8, 16, 18, 12, 22, 20, 18, 28, 30, 20, 24, 36, 24, 40, 42, 24, 46, 42, 32, 52, 40, 36, 58, 60, 36, 48, 66, 44, 70, 72, 40, 60, 78, 54, 82, 64, 56, 88, 72, 60, 72, 96, 60, 100, 102, 48, 106, 108, 72, 112, 88, 72, 96, 110, 80, 100, 126, 84, 130 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Bisection of A000010 (cf. A062570). LINKS T. D. Noe, Table of n, a(n) for n = 0..10000 John Brillhart, John, J. S. Lomont, and Patrick Morton, Cyclotomic properties of the Rudin-Shapiro polynomials, J. Reine Angew. Math. 288 (1976), 37-65; see Table 2; MR0498479 (58 #16589). - From N. J. A. Sloane, Jun 06 2012 V. I. Levenshtein, Conflict-avoiding codes and cyclic triple systems, Problemy Peredachi Informatsii, 43 (No. 3, 2007), 39-53 (in Russian). V. I. Levenshtein, Conflict-avoiding codes and cyclic triple systems, Problems of Information Transmission, 43 (2007), 199-212 (translation from Russian). MATHEMATICA Table[EulerPhi[2 n + 1], {n, 0, 80}] (* Vincenzo Librandi, Jul 16 2019 *) PROG (MAGMA) [EulerPhi(2*n+1): n in [0..70]]; // Vincenzo Librandi, Jul 16 2019 CROSSREFS Cf. A000010, A062570. Sequence in context: A070229 A248835 A053568 * A060685 A073353 A254734 Adjacent sequences:  A037222 A037223 A037224 * A037226 A037227 A037228 KEYWORD nonn AUTHOR 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.

Last modified August 23 11:24 EDT 2019. Contains 326222 sequences. (Running on oeis4.)