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 A145837 Indices of primes in A005891(n). 0
 3, 8, 11, 15, 20, 23, 36, 44, 47, 48, 60, 68, 71, 75, 83, 84, 87, 92, 111, 116, 128, 132, 143, 144, 156, 159, 164, 167, 168, 183, 192, 200, 204, 207, 215, 224, 228, 231, 236, 239, 264, 272, 287, 299, 300, 303, 312, 315, 320, 323, 356, 359, 360, 363, 372, 387 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Corresponding centered pentagonal primes are listed in A145838 = {31, 181, 331, 601, 1051, 1381, 3331, ...}. LINKS Eric Weisstein's World of Mathematics, Centered Pentagonal Number FORMULA A005891(a(n)) = A145838(n) MATHEMATICA (Position[LinearRecurrence[{3, -3, 1}, {1, 6, 16}, 400], _?PrimeQ]// Flatten)-1 (* Harvey P. Dale, Sep 08 2018 *) CROSSREFS Cf. A145838 = Primes in A005891. Cf. A005891 = Centered pentagonal numbers: (5n^2+5n+2)/2. Sequence in context: A234431 A310282 A081858 * A111132 A188473 A003234 Adjacent sequences:  A145834 A145835 A145836 * A145838 A145839 A145840 KEYWORD nonn AUTHOR Alexander Adamchuk, Mar 21 2009 EXTENSIONS Extended by R. J. Mathar, Mar 26 2009 Edited by N. J. A. Sloane, Apr 06 2009 STATUS approved

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Last modified April 25 04:14 EDT 2019. Contains 322451 sequences. (Running on oeis4.)