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A059168 Primes in which digits alternately rise and fall (or vice versa); sometimes called undulating primes. 3
2, 3, 5, 7, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 131, 151, 163, 173, 181, 191, 193, 197, 241, 251, 263, 271, 281, 283, 293, 307, 313, 317, 353, 373, 383, 397, 401, 409, 419, 439, 461, 463, 487, 491 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

REFERENCES

C. A. Pickover, "Wonders of Numbers", Oxford New York 2001, Chapter 52, pp. 123-124, 316-317.

LINKS

Table of n, a(n) for n=0..57.

C. A. Pickover, "Wonders of Numbers, Adventures in Mathematics, Mind and Meaning," Zentralblatt review

MATHEMATICA

d[n_]:=Differences[IntegerDigits[n]]; mQ[n_]:=MemberQ[d[n], 0]==False; a[n_]:=DeleteDuplicates[Sign[Take[d[n], {1, -1, 2}]]]; b[n_]:=DeleteDuplicates[Sign[Take[d[n], {2, -1, 2}]]]; t={}; Do[p=Prime[n]; If[mQ[p], If[Length[IntegerDigits[p]]<=2, AppendTo[t, p], If[Length[a[p]]==Length[b[p]]==1 && a[p][[1]]!=b[p][[1]], AppendTo[t, p]]]], {n, 95}]; t (* Jayanta Basu, May 08 2013 *)

CROSSREFS

Cf. A032758, A059170.

Sequence in context: A233009 A243535 A050757 * A032758 A106118 A029743

Adjacent sequences:  A059165 A059166 A059167 * A059169 A059170 A059171

KEYWORD

nonn,base,easy

AUTHOR

N. J. A. Sloane, Feb 14 2001

EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), Feb 15 2001

STATUS

approved

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Last modified September 23 21:28 EDT 2017. Contains 292391 sequences.