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 A158652 Any two consecutive digits in the sequence sum up to a prime. 9
 1, 2, 3, 4, 7, 41, 43, 47, 49, 83, 85, 89, 202, 302, 303, 411, 412, 502, 503, 830, 2020, 2021, 2023, 2025, 2029, 2030, 2032, 3020, 3021, 4111, 4112, 5020, 5021, 6111, 6112, 9202, 9203, 20202, 30202, 30203, 41111, 41112, 50202, 50203, 83020, 202020 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(1)=1 and a(n) is always the smallest integer > a(n-1) not leading to a contradiction. Terms computed by M. F. Hasler. From M. F. Hasler, Mar 24 2009: (Start) After the initial 2,3,4,7,41,43,47,49,83,85,89, the following pattern repeats: 202,302,303, 411,412,502,503,830, 2020,2021,2023,2025,2029,2030,2032,3020,3021, 4111,4112,5020,5021,6111,6112,9202,9203, with each time two extra digits (either 02 or 11): 20202,30202,30203, 41111,41112,50202,50203,83020, 202020,202021,202023,202025,202029,202030,202032,302020,302021, 411111,411112,502020,502021,611111,611112,920202,920203, and so on. (End) LINKS Robert G. Wilson v, Table of n, a(n) for n=1..100 Eric Angelini, Chiffres consecutifs dans quelques suites E. Angelini, Chiffres consecutifs dans quelques suites [Cached copy, with permission] MATHEMATICA f[s_List] := Block[{k = s[[ -1]] + 1, ls = Mod[ s[[ -1]], 10]}, While[ Union@ PrimeQ[ Plus @@@ Partition[ Join[{ls}, IntegerDigits@ k], 2, 1]] != {True}, k++ ]; Append[s, k]]; Nest[f, {1}, 45] (* Robert G. Wilson v, Apr 05 2009 *) CROSSREFS Cf. A152603-A152610. Sequence in context: A094313 A214914 A070527 * A127074 A328322 A109617 Adjacent sequences:  A158649 A158650 A158651 * A158653 A158654 A158655 KEYWORD base,nonn AUTHOR Eric Angelini, Mar 23 2009 STATUS approved

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Last modified October 22 07:29 EDT 2019. Contains 328315 sequences. (Running on oeis4.)