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 A175212 Numbers n such that A000975(n-1)/n is an integer. Also numbers n such that arithmetic mean of the first n Jacobsthal numbers is an integer. 1
 1, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Contains the subsequence A066488 and differs therefore from A140475. [From R. J. Mathar, Aug 09 2010] LINKS R. J. Mathar, Table of n, a(n) for n = 1..9970 EXAMPLE Arithmetic mean of partial sums of Jacobsthal numbers is an integer : 0/1=0 n=1; (0+1+1+3+5)/5=2 n=5; (0+1+1+3+5+11+21)/7=6 n=7; (0+1+1+3+5+11+21+43+85+171+341)/11=62 n=11 etc. CROSSREFS Cf. A000975, A001045 Sequence in context: A140475 A171577 A215848 * A240710 A115232 A020626 Adjacent sequences:  A175209 A175210 A175211 * A175213 A175214 A175215 KEYWORD easy,nonn AUTHOR Ctibor O. Zizka, Mar 06 2010 EXTENSIONS Term 34 removed, sequence extended and index in definition corrected by R. J. Mathar, Mar 29 2010 STATUS approved

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Last modified January 24 16:32 EST 2020. Contains 331204 sequences. (Running on oeis4.)