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 A115233 Primes p which have a unique representation as p = 2^i + q^j where i >= 0, j >= 1, q = odd prime. 3
 5, 127, 163, 179, 191, 193, 223, 239, 251, 269, 311, 337, 389, 419, 431, 457, 491, 547, 557, 569, 599, 613, 653, 659, 673, 683, 719, 739, 787, 821, 839, 853, 883, 911, 929, 953, 967, 977, 1117, 1123, 1201, 1229, 1249, 1283, 1289, 1297, 1303, 1327, 1381, 1409, 1423, 1439, 1451, 1471, 1481, 1499 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE 5 = 2+3 belongs to the sequence, but 23 = 2^2+19^1 = 2^4+7^1 does not. MATHEMATICA maxp = 1500; Clear[cnt]; cnt[_] = 0; pp = Prime[Range[PrimePi[maxp]]]; Do[p = 2^i + q^j; If[p <= maxp && PrimeQ[p], cnt[p] = cnt[p] + 1], {i, 0, Log[2, maxp] // Ceiling}, {j, 1, Log[3, maxp] // Ceiling}, {q, Rest[pp]} ]; Select[pp, cnt[#] == 1&] (* Jean-François Alcover, Aug 04 2018 *) CROSSREFS Subsequence of A115232. Cf. A115230, A115231. Cf. A000079, A061345. Sequence in context: A059486 A071196 A357133 * A157438 A142803 A208859 Adjacent sequences: A115230 A115231 A115232 * A115234 A115235 A115236 KEYWORD nonn AUTHOR Reinhard Zumkeller, Jan 17 2006 EXTENSIONS Recomputed (based on recomputation of A115230) by R. J. Mathar and Reinhard Zumkeller, Apr 29 2010. Edited by N. J. A. Sloane, Apr 30 2010 Data corrected by Jean-François Alcover, Aug 04 2018 STATUS approved

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Last modified December 9 17:46 EST 2022. Contains 358703 sequences. (Running on oeis4.)