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 A027388 Write digits for n, count endpoints (version 3). 3
 0, 2, 2, 2, 2, 2, 1, 4, 0, 1, 2, 4, 4, 4, 4, 4, 3, 6, 2, 3, 2, 4, 4, 4, 4, 4, 3, 6, 2, 3, 2, 4, 4, 4, 4, 4, 3, 6, 2, 3, 2, 4, 4, 4, 4, 4, 3, 6, 2, 3, 2, 4, 4, 4, 4, 4, 3, 6, 2, 3, 1, 3, 3, 3, 3, 3, 2, 5, 1, 2, 4, 6, 6, 6, 6, 6, 5, 8, 4, 5, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Number of endpoints: 0,8 - zero, 6,9 - one, 1,2,3,4,5 - two, 7 - four. - Michael B. Porter, Oct 28 2017 LINKS FORMULA a(10*n + d) = a(n) + e where e is the number of endpoints of single digit d. - David A. Corneth, Oct 28 2017 EXAMPLE The digit 1 has two endpoints, and the digit 8 has no endpoints, so a(18) = 2. - Michael B. Porter, Oct 28 2017 PROG (PARI) a(n)=vecsum(apply(d->[0, 2, 2, 2, 2, 2, 1, 4, 0, 1][d+1], digits(n))); \\ based on program for A027386 by Andrew Howroyd, Michael B. Porter, Oct 28 2017 CROSSREFS Cf. A027386, A027387, A027389, A055642, A100910, A102683, A268643. Sequence in context: A133563 A104518 A329030 * A114295 A004216 A076489 Adjacent sequences:  A027385 A027386 A027387 * A027389 A027390 A027391 KEYWORD nonn,base AUTHOR EXTENSIONS a(6) corrected by Michael B. Porter, Oct 28 2017 (per Andrew Howroyd) a(27) to a(80) by Michael B. Porter, Oct 28 2017 STATUS approved

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Last modified October 1 12:50 EDT 2020. Contains 337443 sequences. (Running on oeis4.)