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 A178961 Partial sums of number of symmetric foldings of a strip of n stamps (A001010). 0
 1, 3, 5, 9, 15, 23, 41, 61, 117, 165, 343, 475, 1049, 1397, 3267, 4275, 10419, 13231, 33545, 41965, 109499, 133895, 359367, 434123, 1189795, 1412351, 3952757, 4646449, 13211071, 15318819, 44260077, 50916453, 148927917, 169476849 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Number of symmetric foldings of a strip of <= n stamps. The subsequence of primes begins 3, 5, 23, 41, 61, 1049, 1412351. LINKS FORMULA a(n) = SUM[i=1..n] A001010(i). EXAMPLE a(13) = 1 + 2 + 2 + 4 + 6 + 8 + 18 + 20 + 56 + 48 + 178 + 132 + 574 = 1049 is prime. CROSSREFS Cf. A001010. Sequence in context: A118403 A033498 A147493 * A147509 A057259 A045599 Adjacent sequences:  A178958 A178959 A178960 * A178962 A178963 A178964 KEYWORD nonn AUTHOR Jonathan Vos Post, Dec 31 2010 STATUS approved

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Last modified June 25 03:40 EDT 2021. Contains 345449 sequences. (Running on oeis4.)