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A160792
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Vertex number of a rectangular spiral related to prime numbers. The distances between nearest edges of the spiral that are parallel to the initial edge are the prime numbers, while the distances between nearest edges perpendicular to the initial edge are all one.
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5
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0, 1, 3, 5, 10, 13, 23, 27, 44, 49, 77, 83, 124, 131, 189, 197, 274, 283, 383, 393, 522, 533, 693, 705, 902, 915, 1153, 1167, 1448, 1463, 1791, 1807, 2188, 2205, 2645, 2663, 3164, 3183, 3751, 3771, 4410, 4431, 5143, 5165, 5956, 5979, 6853, 6877, 7840, 7865
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| First differences give A160793. - Omar E. Pol, Oct 31 2011
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LINKS
| Nathaniel Johnston, Table of n, a(n) for n = 0..5000
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FORMULA
| a(2n) = a(2n-1) + sum(prime(j),j=1..n), a(2n+1) = a(2n) + n + 1 for n >= 1. - Nathaniel Johnston, Jun 16 2011
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MAPLE
| A160792 := proc(n) option remember: if(n<=1)then return n: fi: if(n mod 2 = 0)then return procname(n-1)+add(ithprime(j), j=1..n/2): fi: return procname(n-1)+ceil(n/2): end: seq(A160792(n), n=0..49); # Nathaniel Johnston, Jun 16 2011
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CROSSREFS
| Cf. A000040, A160790, A160791.
Sequence in context: A200919 A165718 A031878 * A137395 A001767 A048214
Adjacent sequences: A160789 A160790 A160791 * A160793 A160794 A160795
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KEYWORD
| easy,nonn
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AUTHOR
| Omar E. Pol (info(AT)polprimos.com), May 29 2009
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EXTENSIONS
| Terms after a(10) and edited by Nathaniel Johnston (nathaniel(AT)nathanieljohnston.com), Jun 16 2011
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