A037282 Scan n from left to right once, erasing any primes.

1, 0, 0, 4, 0, 6, 0, 8, 9, 10, 0, 1, 0, 14, 1, 16, 0, 18, 0, 0, 1, 0, 0, 4, 0, 6, 0, 8, 0, 0, 0, 0, 0, 4, 0, 6, 0, 8, 9, 40, 0, 4, 0, 44, 4, 46, 0, 48, 49, 0, 1, 0, 0, 4, 0, 6, 0, 8, 0, 60, 0, 6, 6, 64, 6, 66, 0, 68, 69, 0, 0, 0, 0, 4, 0, 6, 0, 8, 0, 80, 81, 8, 0, 84, 8, 86, 8, 88, 0, 90, 91, 9, 9, 94, 9

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• base
• easy

Examples

			a(7) = a(77) = 0, a(1294) = 14.
		

Programs

Maple

catDigs := proc(L,i,j) local k ; add(L[k]*10^(k-i),k=i..j) ; end: A037282 := proc(n) local L,w,i,lenL,a ; L := convert(n,base,10) ; lenL := nops(L) ; for w from lenL to 1 by -1 do for i from lenL-w+1 to 1 by -1 do a := catDigs(L,i,i+w-1) ; if isprime(a) then a := catDigs(L,1,i-1)+10^(i-1)*catDigs(L,i+w,lenL) ; RETURN(A037282(a)) ; fi ; od: od: RETURN(n) ; end: seq(A037282(n),n=1..150) ; # R. J. Mathar, Oct 12 2007

Extensions

More terms from R. J. Mathar, Oct 12 2007