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A089360
Prime worms.
0
101, 131, 151, 181, 191, 313, 353, 373, 383, 727, 757, 787, 797, 919, 929, 12101, 14741, 18181, 32323, 34543, 35353, 35753, 72727, 74747, 75797, 78787, 79757, 94949, 95959, 97579, 1012321, 1212121, 1414741, 1474141, 1616161, 3131353
OFFSET
1,1
COMMENTS
While some palindromic primes are included, there are other criteria for addition to this sequence.
REFERENCES
Carlos Rivera's primepuzzles.net, Puzzle 246
FORMULA
From sequence of primes beginning with 3-digits, select those with identical first and last digits; no adjacent digits identical; and absolute value of sequential differences of paired digits a constant.
EXAMPLE
a(15)=12101; first and last digits = 1; no identical adjacent digits; abs(1-2)=1;abs(2-1)=1; abs(1-0)=1; abs(0-1)=1; the worm is 1.
CROSSREFS
Cf. A089291, A089315-89317, A048398-48405.
Sequence in context: A154270 A056730 A077798 * A056728 A085112 A059758
KEYWORD
easy,nonn,base
AUTHOR
Enoch Haga, Dec 27 2003
STATUS
approved