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A113625
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Irregular triangle in which the n-th row contains all primes having digit sum n (not containing the digit '0') in increasing order.
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1
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2, 11, 3, 13, 31, 211, 5, 23, 41, 113, 131, 311, 2111, 7, 43, 61, 151, 223, 241, 313, 331, 421, 1123, 1213, 1231, 1321, 2113, 2131, 2221, 2311, 3121, 4111, 11113, 11131, 11311, 12211, 21121, 21211, 22111, 111121, 111211, 112111, 17, 53, 71, 233, 251, 431, 521
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OFFSET
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2,1
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COMMENTS
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The number of primes in the n-th row is A073901(n). The smallest prime in the n-th row is A067180(n). The largest prime in the n-th row is A069869(n).
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LINKS
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EXAMPLE
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Starting with row 2, the table is
2, 11
3
13, 31, 211
5, 23, 41, 113, 131, 311, 2111
none
7, 43, 61, 151, 223, 241, 313, 331, 421, 1123,...
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MAPLE
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with(combinat):
b:= proc(n, i, l) option remember; `if`(n=0, select(isprime,
map(x-> parse(cat(x[])), permute(l))), `if`(i<1, [],
[seq(b(n-i*j, i-1, [l[], i$j])[], j=0..n/i)]))
end:
T:= n-> sort(b(n, 9, []))[]:
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MATHEMATICA
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Table[If[n > 3 && Mod[n, 3] == 0, {}, p = IntegerPartitions[n]; u = {}; Do[t = Permutations[i]; u = Union[u, Select[FromDigits /@ t, PrimeQ]], {i, p}]; u], {n, 2, 14}]
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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