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A113625 Irregular triangle in which the n-th row contains all primes having digit sum n (not containing the digit '0') in increasing order. 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,1
COMMENTS
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).
LINKS
Alois P. Heinz, Rows n = 2..17, flattened (Rows n = 2..14 from T. D. Noe)
EXAMPLE
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,...
MAPLE
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, []))[]:
seq(T(n), n=2..8); # Alois P. Heinz, May 25 2013
MATHEMATICA
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}]
CROSSREFS
Sequence in context: A275536 A060002 A110741 * A279237 A090323 A127668
KEYWORD
base,tabf,nonn,look
AUTHOR
Amarnath Murthy, Nov 10 2005
EXTENSIONS
Edited, corrected and extended by Stefan Steinerberger, Aug 10 2007
Edited by T. D. Noe, Jan 25 2011
STATUS
approved

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Last modified April 19 23:15 EDT 2024. Contains 371798 sequences. (Running on oeis4.)